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Question 1
Correct
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Severe vomiting and diarrhoea were reported by a 25-year-old man. He's dehydrated and needs intravenous fluids to rehydrate. You give him cyclizine as part of his treatment.
What is cyclizine's main mechanism of action?Your Answer: Antihistamine action
Explanation:Cyclizine is a piperazine derivative that functions as an antihistamine (H1-receptor antagonist). To prevent nausea and vomiting, it is thought to act on the chemoreceptor trigger zone (CTZ) and the labyrinthine apparatus. It has a lower antimuscarinic effect as well.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 2
Incorrect
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Which of the following statements is correct regarding anti-D immunoglobulin?
Your Answer: It aims to prevent haemorrhagic disease of the newborn.
Correct Answer: It is administered as part of routine antenatal care for rhesus-negative mothers.
Explanation:In all non-sensitised pregnant women who are RhD-negative, it is recommended that routine antenatal anti-D prophylaxis is offered. Even if there is previous anti-D prophylaxis, use of routine antenatal anti-D prophylaxis should be given for a sensitising event early in the same pregnancy. Postpartum anti-D prophylaxis should also be given even if there has been previous routine antenatal anti-D prophylaxis or antenatal anti-D prophylaxis for a sensitising event in the same pregnancy.
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This question is part of the following fields:
- Immunoglobulins And Vaccines
- Pharmacology
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Question 3
Correct
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A 28-year-old asthmatic patient is seen in the Emergency Department following an acute exacerbation. His symptoms start to improve when your consultant gives him a high dose of IV aminophylline.
Which of the following is correct mechanism of action of aminophylline ?Your Answer: Inhibition of phosphodiesterase
Explanation:Aminophylline has the following properties:
Phosphodiesterase inhibitor that increases intracellular cAMP and relaxes smooth muscle in the bronchial airways and pulmonary blood vessels.
Mast cell stabilization is achieved by using a non-selective adenosine receptor antagonist. -
This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 4
Incorrect
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A 60-year-old man with insulin-controlled diabetes mellitus asks you about how his ability to drive is affected. He owns a car as well as a motorcycle.
Which of the following statements about driving with diabetes under insulin control is correct?Your Answer: He must not have had more than 2 episodes of hypoglycaemia requiring the assistance of others in the past 12 months
Correct Answer: He must monitor his blood glucose levels every 2 hours whilst driving
Explanation:The DVLA sends a detailed information sheet about their licence and driving to all drivers with diabetes mellitus. The primary danger of driving while diabetic is hypoglycaemia.
The DVLA must be notified of the following diabetic patients:
All of the drivers are on insulin. (Licenses are being reviewed more frequently.)
Those who are at high risk of hypoglycaemia and have had more than one episode of severe hypoglycaemia in the previous year. (Severe hypoglycaemia is defined as requiring the assistance of another person to manage.)
Those who are unaware of their hypoglycaemia
Anyone who has ever been in a car accident due to hypoglycaemia
Anyone with diabetic retinopathy who needs laser treatment (to both eyes or to a second eye if sight only in one eye)
Patients with diabetes complications that impair their ability to drive.To drive, drivers with insulin-treated diabetes must meet the following requirements:
They need to be aware of hypoglycaemia.
They must not have had more than one episode of hypoglycaemia in the previous 12 months that necessitated the assistance of another person.
They must check their blood glucose levels no later than 2 hours before the first journey.
While driving, they must check their blood glucose levels every two hours.
The visual acuity and visual field standards must be met.Any significant changes in their condition must be reported to the DVLA. Furthermore, on days when they are not driving, group 2 licence holders must test their blood glucose twice daily using a metre that can store three months’ worth of readings.
In addition to this advice, the DVLA also offers the following advice to diabetic patients:
When taking tablets that have the potential to cause hypoglycaemia (such as sulfonylureas and glinides), monitoring may be necessary if there has been more than one episode of severe hypoglycaemia.
Drivers must show good control and be able to recognise hypoglycaemia.
Verify that your vision meets the required standard.If a patient feels hypoglycaemic or has a blood glucose level of less than 4.0 mmol/L, they should not drive. Driving should not be resumed until blood glucose levels have returned to normal, which should take 45 minutes.
If there are any warning signs, patients should carry rapidly absorbed sugar in their vehicle and stop, turn off the ignition, and eat it.
If resuscitation is required, a card stating which medications they are taking should be carried.
If hypoglycaemia causes an accident, a diabetic driver may be charged with driving under the influence of drugs.
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This question is part of the following fields:
- Endocrine Pharmacology
- Pharmacology
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Question 5
Correct
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A 39-year-old man with a long history of depression presents after intentionally overdoing his heart medication. Verapamil immediate-release 240 mg is the tablet he takes for this condition, he says. He took the pills about 30 minutes ago, but his wife discovered him right away and rushed him to the emergency room.
Which of the following is a verapamil toxicity?Your Answer: Negative inotropy
Explanation:Overdosing on calcium-channel blockers should always be taken seriously and regarded as potentially fatal. Verapamil and diltiazem are the two most lethal calcium-channel blockers in overdose. These work by binding the alpha-1 subunit of L-type calcium channels, preventing calcium from entering the cell. In cardiac myocytes, vascular smooth muscle cells, and islet beta-cells, these channels play an important role.
The following summarises the toxicity of calcium-channel blockers:
Cardiac effects
Vascular smooth muscle tone affects
Metabolic effects
Excessive negative inotropy: myocardial depression
Negative chronotropy: sinus bradycardia
Negative dromotropy: atrioventricular node blockade
Decreased afterload
Systemic hypotension
Coronary vasodilation
Hypoinsulinaemia
Calcium channel blocker-induced insulin resistance -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 6
Incorrect
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A 55-year-old woman with mild dyspepsia seeks advice from her pharmacist on how to deal with her symptoms. In the first instance, the pharmacist advises her to take an over-the-counter antacid. She buys an antacid that contains aluminium hydroxide, which relieves her symptoms but has a negative side effect.
She's most likely to have developed which of the following side effects?Your Answer: Aluminium toxicity
Correct Answer: Constipation
Explanation:Aluminium hydroxide is a common antacid that is used to treat ulcer dyspepsia and non-erosive gastro-oesophageal reflux disease.
When antacids containing aluminium salts are given to patients with renal impairment, there is a risk of accumulation and aluminium toxicity. If renal function is normal, aluminium accumulation does not appear to be a risk.
Because it reduces gastrointestinal phosphate absorption, aluminium hydroxide can also be used to treat hyperphosphatemia in patients with renal failure.
Magnesium-based antacids are generally laxative, whereas aluminium-based antacids can be constipating. Renal impairment, angioedema, and anaphylaxis are not significantly increased.
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This question is part of the following fields:
- Gastrointestinal Pharmacology
- Pharmacology
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Question 7
Correct
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An 80-year-old female complains of chest pain characteristic of angina. A dose of glyceryl trinitrate (GTN) is administered that resolves the chest pain rapidly.
Which ONE of the following is released on the initial metabolism of GTN?Your Answer: Nitrite ions
Explanation:Angina pectoris is the most common symptom of ischemic heart disease and presents with chest pain relieved by rest and nitro-glycerine.
Nitrates are the first-line treatment to relieve chest pain caused by angina. The commonly used nitrates are:
1. Glyceryl trinitrate
2. Isosorbide dinitrateThe nitrate drugs are metabolized in the following steps:
1. Release Nitrite ions (NO2-), which are then converted to nitric oxide (NO) within cells.
2. NO activates guanylyl cyclase, which causes an increase in the intracellular concentration of cyclic guanosine-monophosphate (cGMP) in vascular smooth muscle cells.
3. Relaxation of vascular smooth muscle.Although nitrates are potent coronary vasodilators, their principal benefit in the management of angina results from a predominant mechanism of venous dilation:
– Bigger veins hold more blood
– Takes blood away from the left ventricle
– Lowers LVEDV (preload), LA pressure
– Less pulmonary oedema → improved dyspnoea -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 8
Incorrect
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Which of the following is NOT a common side effect of diazepam:
Your Answer: Ataxia
Correct Answer: Bradycardia
Explanation:Adverse effects include:
Drowsiness and lightheadedness
Confusion and ataxia (especially in the elderly), amnesia, muscle weakness
Headache, vertigo, tremor, dysarthria, hypotension, decreased libido, erectile dysfunction, gynaecomastia, urinary retention
Paradoxical effects such as talkativeness, excitement, irritability, aggression, anti-social behaviour, and suicidal ideation
Withdrawal symptoms, for example anxiety, depression, anorexia, impaired concentration, insomnia, abdominal cramps, palpitations, tremor, tinnitus and perceptual disturbances
Tolerance and dependence (people who use benzodiazepines longer term can develop tolerance and eventual dependence) -
This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 9
Incorrect
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You are reviewing a patient in the Emergency Department brought in by the ambulance team from a burning building. After examination, you decide to intubate the patient due to laryngeal oedema. The induction agent you are planning to use is propofol.
Which one of the following statements about this medicine is TRUE?Your Answer: It increases systemic vascular resistance
Correct Answer: It decreases cardiac output by approximately 20%
Explanation:Propofol is a short-acting anaesthetic that is thought to work by potentiating GABA and glycine. It induces anterograde amnesia and anaesthetic effects and is used to induce anaesthesia, outpatient surgeries and preoperative sedation. The dose for induction of anaesthesia is 1.5-2.5mg/kg. The dose for maintenance of anaesthesia is 4-12 mg/kg/hour. Following intravenous injection, propofol acts within 30 seconds and its duration of action is 5-10 minutes.
Propofol produces a 15-25% decrease in blood pressure and systemic vascular resistance without a compensatory increase in heart rate. It is negatively inotropic and decreases cardiac output by approximately 20%.
The main side effects of propofol are:
Pain on injection (in up to 30%)
Hypotension
Transient apnoea
Hyperventilation
Coughing and hiccough
Headache
Thrombosis and phlebitis -
This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 10
Incorrect
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Regarding inflammatory bowel disease, acute mild to moderate disease of the rectum or rectosigmoid should be treated initially with:
Your Answer: Oral steroid
Correct Answer: Local aminosalicylate
Explanation:Acute mild to moderate disease affecting the rectum (proctitis) or the rectosigmoid is treated initially with local application of an aminosalicylate; alternatively, a local corticosteroid can be used but it is less effective. A combination of a local aminosalicylate and a local corticosteroid can be used for proctitis that does not respond to a local aminosalicylate alone.
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This question is part of the following fields:
- Gastrointestinal
- Pharmacology
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Question 11
Correct
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The patients listed below have been diagnosed with a variety of ailments.
In which of the following situations would aspirin be an effective treatment option?Your Answer: A 36-year-old with an acute migraine (dose of 900-1000 mg)
Explanation:A study published in the Cochrane Database of Systematic Reviews in 2010 found that a single 1000-mg dose of aspirin is effective in treating acute migraine. It was discovered that 24 percent of aspirin users were pain-free after two hours, compared to 11 percent of placebo users. Because the BNF recommends a maximum dose of 900 mg for analgesia and most non-proprietary aspirin comes in a dose of 300 mg, a dose of 900 mg is frequently prescribed in the UK.
Because aspirin is not recommended for children under the age of 16 due to the risk of Reye’s syndrome, it would be inappropriate to give it to the 12-year-old with the viral URTI.
For uncomplicated dental pain, aspirin is an acceptable option, but not for patients who are taking warfarin. The combination of aspirin’s antiplatelet action and warfarin’s anticoagulation properties puts the patient at high risk of bleeding. Furthermore, aspirin can deplete the therapeutic levels of warfarin by displacing it from plasma proteins. It would be better to use another NSAID or analgesic.
In gout, aspirin should be avoided because it reduces urate clearance in the urine and interferes with the action of uricosuric agents. Naproxen, diclofenac, and indomethacin are better options.
Although aspirin is useful for inflammatory pains, the dose of aspirin required for an adequate analgesic effect in severe pain is associated with significant side effects. Naproxen would be a better first-line treatment option.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 12
Incorrect
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Which of the following is NOT a typical side effect of thiopental sodium:
Your Answer: Involuntary muscle movements on induction
Correct Answer: Seizures
Explanation:Extravasation of thiopental during injection can lead to tissue damage. Accidental intra-arterial injection causes vasospasm and may lead to thrombosis and tissue necrosis. Other side effects include involuntary muscle movements on induction, cough and laryngospasm, arrhythmias, hypotension, headache and hypersensitivity reactions. Thiopental sodium has anticonvulsant properties and does not cause seizures.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 13
Incorrect
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Regarding atracurium, which of the following statements is CORRECT:
Your Answer:
Correct Answer: Effects such as flushing, tachycardia and hypotension can occur due to significant histamine release.
Explanation:Cardiovascular effects such as flushing, tachycardia, hypotension and bronchospasm are associated with significant histamine release; histamine release can be minimised by administering slowly or in divided doses over at least 1 minute. Atracurium undergoes non-enzymatic metabolism which is independent of liver and kidney function, thus allowing its use in patients with hepatic or renal impairment. Atracurium has no sedative or analgesic effects. All non-depolarising drugs should be used with care in patients suspected to be suffering with myasthenia gravis or myasthenic syndrome, as patients with these conditions are extremely sensitive to their effects and may require a reduction in dose.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 14
Incorrect
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Which of the following side effects would you least associated with ciprofloxacin:
Your Answer:
Correct Answer: Folate deficiency
Explanation:Common side effects include diarrhoea, dizziness, headache, nausea and vomiting.
Other adverse effects include: Tendon damage (including rupture), Seizures (in patients with and without epilepsy), QT-interval prolongation, Photosensitivity and Antibiotic-associated colitis -
This question is part of the following fields:
- Infections
- Pharmacology
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Question 15
Incorrect
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An 82-year-old woman was brought in an ambulance to the Emergency Department with a 1-hour history of left-sided weakness and dysphasia.
A CT scan is performed, and primary intracerebral haemorrhage is excluded as a possible cause. She is prepared for thrombolysis when her blood pressure is recorded at 200/115 mmHg.
Out of the following, which step would be the most appropriate as the next step in her management?Your Answer:
Correct Answer: Labetalol 10 mg IV
Explanation:A patient suffering from acute ischemic stroke can commonly present with hypertensive emergencies. Thrombolytic therapy is contraindicated in a patient with:
1. Systolic blood pressure greater than 185 mmHg
2. Diastolic blood pressure greater than 110 mmHgBut delaying thrombolytic therapy is associated with increased morbidity in patients with acute ischemic stroke.
Managing high blood pressure in acute ischemic stroke requires a slower and more controlled reduction in BP. In the presence of an ischaemic stroke, rapid reduction of MAP can compromise blood flow, causing further ischemia and worsening of the neurological deficit.
Intravenous labetalol is the agent of choice. The dose is 10 mg IV over 1-2 minutes. This dose can be repeated, or an infusion can be set up that runs at 2-8 mg/minute. Thrombolysis can be performed once the blood pressure is brought down to less than 180/105 mmHg.
A nitrate infusion (for example, Isoket) can be used as an alternative in patients with contraindications to the use of beta-blockers (e.g., asthma, heart block, cardiac failure).
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 16
Incorrect
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What is the mechanism of action of penicillin antibiotics:
Your Answer:
Correct Answer: Inhibition of bacterial cell wall synthesis
Explanation:Penicillins and the other ß-lactam antibiotics are bactericidal. They produce their antimicrobial action by preventing cross-linkage between the linear peptidoglycan polymer chains that make up the bacterial cell wall. They, therefore, inhibit cell wall synthesis.
The integrity of the ß-lactam ring is essential for antimicrobial activity. Many bacteria (including most Staphylococci) are resistant to benzylpenicillin and phenoxymethylpenicillin because they produce enzymes (penicillinases, ß-lactamases) that open the ß-lactam ring. -
This question is part of the following fields:
- Infections
- Pharmacology
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Question 17
Incorrect
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Herpes simplex encephalitis has a predilection for which of the following sites:
Your Answer:
Correct Answer: Temporal lobe
Explanation:Herpes simplex virus is the most common cause of infective encephalitis and has a predilection for the temporal lobes. Herpes simplex is transmitted through direct contact. It invades skin locally producing skin vesicles by its cytolytic activity.
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This question is part of the following fields:
- Infections
- Microbiology
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Question 18
Incorrect
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The patient is a 66-year-old woman who has troublesome bilateral ankle swelling. This has been happening since she began taking a new antihypertensive medication a few weeks ago.
Which of the following medications is most likely to be the cause of this adverse reaction?Your Answer:
Correct Answer: Amlodipine
Explanation:Amlodipine is a calcium-channel blocker that is frequently used to treat hypertension. Ankle swelling is a very common side effect of calcium-channel blockers, and it occurs quite frequently.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 19
Incorrect
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You contact the intensive care outreach team to inquire about a severely hypotensive resuscitated patient. They make the decision to start a dopamine infusion.
Dopamine primarily has which of the following effects at high doses (>15 g/kg/min)?Your Answer:
Correct Answer: Alpha-adrenergic stimulation
Explanation:Dopamine is a catecholamine that occurs naturally and is used to treat low cardiac output, septic shock, and renal failure. It is both adrenaline and noradrenaline’s immediate precursor.
Dopamine acts on D1 and D2 dopamine receptors in the renal, mesenteric, and coronary beds at low doses (1-5 g/kg/min). Dopamine causes a significant decrease in renal vascular resistance and an increase in renal blood flow at these doses. Within this dose range, it is also involved in central modulation of behaviour and movement.
Dopamine stimulates beta- and alpha-adrenergic receptors directly and indirectly at higher doses. Beta-stimulation predominates at a rate of 5-10 g/kg/min, resulting in a positive inotropic effect that increases cardiac output and coronary blood flow. Alpha-stimulation predominates at infusion rates greater than 15 g/kg/min, resulting in peripheral vasoconstriction and an increase in venous return and systolic blood pressure.
Because clearance varies greatly in critically ill patients, plasma concentrations cannot be predicted reliably from infusion rates.
Dopamine is given as an intravenous infusion, and because extravasation can cause tissue necrosis and sloughing, a central line is usually used (especially at higher doses >240 g/min). In an emergency, however, dopamine can be administered through a large vein (cephalic or basilic) while a central line is being prepared. Alkaline intravenous solutions inactivate it, so sodium bicarbonate should not be infused with it.The following are the most common dopamine side effects:
Nausea and vomiting
Tachycardia
Dysrhythmias
Angina
Hypertension -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 20
Incorrect
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Disease specific immunoglobulin is available for all of the following infectious diseases EXCEPT for:
Your Answer:
Correct Answer: Hepatitis A
Explanation:Disease specific immunoglobulins are available for:
hepatitis B
rabies
tetanus
varicella-zoster
Normal immunoglobulin can be used to confer protection against hepatitis A. -
This question is part of the following fields:
- Immunoglobulins And Vaccines
- Pharmacology
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Question 21
Incorrect
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A 40-year-old man complains of pain and redness in his lower thigh due to an insect bite. He was diagnosed with cellulitis. Select the first-line antibiotic for cellulitis.
Your Answer:
Correct Answer: Flucloxacillin
Explanation:Cellulitis is most commonly caused by bacteria from the group Aß-hemolytic streptococcus.
Cellulitis can be caused by animal bites. For uncomplicated cellulitis, flucloxacillin is the first-line antibiotic. Because it is beta-lactamase stable, it is efficient against Staphylococcus aureus.
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This question is part of the following fields:
- Infections
- Microbiology
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Question 22
Incorrect
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Dexamethasone would be most useful for which of the following conditions:
Your Answer:
Correct Answer: Raised intracranial pressure secondary to malignancy
Explanation:Dexamethasone has a very high glucocorticoid activity in conjunction with insignificant mineralocorticoid activity. This makes it particularly suitable for high-dose therapy in conditions where fluid retention would be a disadvantage such as in the management of raised intracranial pressure or cerebral oedema secondary to malignancy. Dexamethasone also has a long duration of action and this, coupled with its lack of mineralocorticoid action makes it particularly suitable for suppression of corticotropin secretion in congenital adrenal hyperplasia. In most individuals a single dose of dexamethasone at night, is sufficient to inhibit corticotropin secretion for 24 hours. This is the basis of the ‘overnight dexamethasone suppression test’ for diagnosing Cushing’s syndrome.
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This question is part of the following fields:
- Endocrine
- Pharmacology
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Question 23
Incorrect
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Question 24
Incorrect
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An 80-year-old male has presented with chest pain characteristic of angina pectoris. Before initiating treatment with Glyceryl nitrate, you examine the patient and find a murmur. The patient reveals that he has a heart valve disorder, and you immediately put a hold on the GTN order.
Which of the following valve disorders is an absolute contraindication to the use of GTN?Your Answer:
Correct Answer: Mitral stenosis
Explanation:Angina pectoris is the most common symptom of ischemic heart disease and presents with chest pain relieved by rest and nitro-glycerine.
Nitrates are the first-line treatment to relieve chest pain caused by angina. The commonly used nitrates are:
1. Nitro-glycerine (NTG) – angina pectoris (treatment/prophylaxis), acute coronary syndrome, heart failure, hypertension
2. Isosorbide mononitrate (ISMN) – chronic angina pectoris (treatment)
3. Isosorbide dinitrate (ISDN) – angina pectoris (treatment/prophylaxis)The nitrate drugs cause vasodilation via the action of nitric oxide.
The contraindications to the use of nitrate are the following:
1. Allergy to nitrates
2. Concomitant use of phosphodiesterases (PDE) inhibitors such as tadalafil and sildenafil
3. Right ventricular infarction
4. Hypertrophic cardiomyopathy
5. Cardiac tamponade
6. Constrictive pericarditis
7. Hypotensive conditions
8. Hypovolaemia
9. Marked anaemia
10. Mitral stenosis
11. Raised intracranial pressure due to cerebral haemorrhage or head trauma
12. Toxic pulmonary oedema -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 25
Incorrect
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A 60-year-old man comes to your department with complaints of epigastric pain. There is a history of rheumatoid arthritis and he has been taking ibuprofen 200 mg TDS for the last 2 weeks.
The following scenarios would prompt you to consider the co-prescription of a PPI for gastroprotection with NSAIDs EXCEPT?
Your Answer:
Correct Answer: Long-term use for chronic back pain in a patient aged 30
Explanation:The current recommendations by NICE suggest that gastro-protection should be considered if patients have ≥1 of the following:
Aged 65 or older
– Using maximum recommended dose of an NSAID
– History of peptic ulcer or GI bleeding
– Concomitant use of: antidepressants like SSRIs and SNRIs, Corticosteroids, anticoagulants and low dose aspirin
– Long-term NSAID usage for: long-term back pain if older than 45 and patients with OA or RA at any ageThe maximum recommended dose of ibuprofen is 2.4 g daily and this patient is on 400 mg of ibuprofen TDS.
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This question is part of the following fields:
- Musculoskeletal Pharmacology
- Pharmacology
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Question 26
Incorrect
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A 32-year-old asthmatic patient on theophylline as part of her asthma management presents to the Emergency Department with an unrelated medical condition.
Which of these drugs should be avoided?Your Answer:
Correct Answer: Clarithromycin
Explanation:Macrolide antibiotics (e.g. clarithromycin and erythromycin) are cytochrome P450 enzyme inhibitors. They increase blood levels of theophylline leading to hypokalaemia, and potentially increasing the risk of Torsades de pointes when they are prescribed together.
Co-prescription with theophylline should be avoided.
Factors that enhance theophylline clearance include cigarette smoking, carbamazepine, phenobarbital, phenytoin, primidone, and rifampin.
Medications that inhibit clearance include ethanol, ciprofloxacin, erythromycin, verapamil, propranolol, ticlopidine, tacrine, allopurinol, and cimetidine. -
This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 27
Incorrect
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A 15-year-old girl took 20 tablets of paracetamol almost 4 hours ago after her mother for refused to provide her permission for her to go on a girl's trip. The girl is healthy and has no known comorbidities or drug history. Which one of the following is TRUE regarding paracetamol?
Your Answer:
Correct Answer: It is excreted renally
Explanation:Acetaminophen is an acetanilide derivative and is a widely used non-prescription analgesic and antipyretic medication for mild-to-moderate pain and fever.
The route of elimination: Paracetamol is metabolised extensively in the liver and excreted in the urine mainly as inactive glucuronide and sulfate conjugates, <5% is excreted as free (unconjugated) acetaminophen, and >90% of the dose administered is excreted within 24 hours.
It is thought to work by selectively inhibiting COX-1 receptors in the brain and spinal cord: It is categorized by the FDA as an NSAID as it is believed to selectively inhibit cyclo-oxygenase 3 (COX-3) receptors in the brain and spinal cord.
COX-3 is a unique variant of the more known COX-1 and COX-2. It is responsible for the production of prostaglandins in central areas, which sensitizes free nerve endings to the chemical mediators of pain. Therefore, by selectively inhibiting COX-3, paracetamol effectively reduces pain sensation by increasing the pain threshold.
Toxicity is primarily due to glutathione production: Acetaminophen metabolism by the CYP2E1 pathway releases a toxic metabolite known as N-acetyl-p-benzoquinoneimine (NAPQI). NAPQI primarily contributes to the toxic effects of acetaminophen. NAPQI is an intermediate metabolite that is further metabolized by fast conjugation with glutathione. The conjugated metabolite is then excreted in the urine as mercapturic acid. High doses of acetaminophen (overdoses) can lead to hepatic necrosis due to depleting glutathione and high binding levels of reactive metabolite (NAPQI) to important parts of liver cells.
Acetaminophen can be administered orally, rectally, or intravenously. It is predominantly metabolized in the liver, and the elimination half-life is 1-3 hours after a therapeutic dose. But maybe greater than 12 hours after an overdose.
It is primarily metabolized via the cytochrome p450 enzyme system: It is predominantly metabolized in the liver by three main metabolic pathways:
1. Glucuronidation (45-55%)
2. Sulphate conjugation (30-35%)
3. N-hydroxylation via the hepatic cytochrome p450 enzyme system (10-15%) -
This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 28
Incorrect
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A 5-year-old girl is brought into the Paediatric ER for acute seizures. She has been convulsing for the past 18 minutes now and was already two doses of lorazepam in the ambulance. Now, you prepare a phenytoin infusion to abolish the seizures.
According to the APLS algorithm, what dose of phenytoin is advised for a convulsing child at this stage?Your Answer:
Correct Answer: 20 mg/kg over 20 minutes
Explanation:Advanced paediatric life support (APLS) recommends phenytoin as the first choice for second-line anticonvulsant in a patient that continues to seize ten minutes after the second dose of the first-line anticonvulsant (benzodiazepine). (step 3 of the APLS algorithm)
The recommended dose of phenytoin infusion is up at 20 mg/kg over 20 minutes. If the patient has already taken phenytoin as maintenance therapy or is allergic to phenytoin, then a phenobarbitone infusion should be set up at 20 mg/kg over 30-60 minutes.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 29
Incorrect
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The primary mechanism of action of ketamine is:
Your Answer:
Correct Answer: N-methyl-D-aspartate (NMDA)-receptor antagonist
Explanation:Ketamine is a non-competitive antagonist of the calcium-ion channel in the NMDA (N-methyl-D-aspartate) receptor. It further inhibits the NMDA-receptor by binding to its phencyclidine binding site. Ketamine also acts at other receptors as an opioid receptor agonist (analgesic effects), as an muscarinic anticholinergic receptor antagonist (antimuscarinic effects) and by blocking fast sodium channels (local anaesthetic effect).
Overdose may lead to panic attacks and aggressive behaviour; rarely seizures, increased ICP, and cardiac arrest
Very similar in chemical makeup to PCP (phencyclidine), but it is shorter acting and less toxic
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 30
Incorrect
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You have been called to review a patient and his management in the resuscitation room. A very sick patient has been started on mannitol in his treatment protocol.
Out of the following, what is NOT an FDA-recognized indication for the use of mannitol?
Your Answer:
Correct Answer: Congestive cardiac failure
Explanation:Mannitol is the most widely used osmotic diuretic that is most commonly used to reduce cerebral oedema and intracranial pressure.
Mannitol has four FDA approved uses clinically:
1. Reduction of intracranial pressure and brain mass
2. reduce intraocular pressure if this is not achievable by other means
3. promote diuresis for acute renal failure to prevent or treat the oliguric phase before irreversible damage
4. promote diuresis to promote the excretion of toxic substances, materials, and metabolitesIt can be used in rhabdomyolysis-induced renal failure, especially in crush injuries. Mannitol reduces osmotic swelling and oedema in the injured muscle cells and helps restore skeletal muscle function.
It is a low molecular weight compound and can be freely filtered at the glomerulus and not reabsorbed. This way increases the osmolality of the glomerular filtrate and tubular fluid, increasing urinary volume by an osmotic effect. It also does not cross the blood-brain barrier (BBB).
Mannitol causes an expansion of the extracellular fluid space, which may worsen congestive cardiac failure. Contraindications to the use of mannitol include:
1. Anuria due to renal disease
2. Acute intracranial bleeding (except during craniotomy)
3. Severe cardiac failure
4. Severe dehydration
5. Severe pulmonary oedema or congestion
6. Known hypersensitivity to mannitol -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 31
Incorrect
-
A 10-year-old girl presents with polyuria, polydipsia, and stomach pain. She has a history of type I diabetes mellitus. On blood gas analysis, she has metabolic acidosis. Diabetic ketoacidosis (DKA) is diagnosed, and therapy is initiated. She becomes increasingly confused when intravenous fluids and insulin are administered.
Which electrolyte imbalance is the MOST likely reason of the increased confusion
Your Answer:
Correct Answer: Hyponatraemia
Explanation:Because of the shift of water from the intracellular to the extracellular compartment as a result of hyperglycaemia and increased plasma osmolality, dilutional hyponatraemia is common in diabetic ketoacidosis (DKA).
If intravenous fluids are not delivered with caution, hyponatraemia might worsen, which can lead to increased degrees of disorientation. Hyponatraemia has also been linked to an increased risk of cerebral oedema, especially if blood glucose levels drop too quickly following treatment.
Headache, recurrence of vomiting, irritability, Glasgow Coma Scale score, inappropriate heart rate slowing, and rising blood pressure are the most common causes of death in paediatric DKA, and children should be monitored for the symptoms mentioned above. To prevent this from developing, s low osmolarity normalization, attention to glucose and salt levels, as well as hydration over 48 hours, is necessary.
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This question is part of the following fields:
- Musculoskeletal Pharmacology
- Pharmacology
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Question 32
Incorrect
-
Lidocaine's mechanism of action as a local aesthetic is as follows:
Your Answer:
Correct Answer: Blocks influx of Na+ through voltage-gated Na+ channels
Explanation:Local anaesthetics prevent generation/conduction of nerve impulses by reducing sodium permeability and increasing action potential threshold; inhibits depolarization, which results in blockade of conduction
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 33
Incorrect
-
For the treatment of his atrial fibrillation, a 67-year-old man is about to begin taking warfarin. He also takes a number of other medications.
Which of the following medications will prevent warfarin from working?Your Answer:
Correct Answer: Phenytoin
Explanation:Many medications, including warfarin, require cytochrome P450 enzymes for their metabolism. When co-prescribing cytochrome p450 enzyme inducers and inhibitors with warfarin, it’s critical to be cautious.
Inhibitors of the cytochrome p450 enzyme inhibit the effects of warfarin, resulting in a lower INR. To remember the most commonly encountered cytochrome p450 enzyme inducers, use the mnemonic PC BRASS:
P– Phenytoin
C– Carbamazepine
B– Barbiturates
R– Rifampicin
A– Alcohol (chronic ingestion)
S– Sulphonylureas
S– Smoking -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 34
Incorrect
-
During her pregnancy, a 28-year-old lady was given an antibiotic. The neonate is born with bilateral deafness as a result of this.
From the following antibiotics, which one is most likely to cause this side effect?Your Answer:
Correct Answer: Gentamicin
Explanation:Aminoglycosides cross the placenta and are linked to poisoning of the 8th cranial nerve in the foetus, as well as permanent bilateral deafness.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 35
Incorrect
-
A 6-year-old girl is brought into the paediatric emergency room by her mother in a state of high-grade fever and extreme irritability. She is also reluctant to urinate as it is associated with lower abdominal pain and stinging. She has no history of any UTIs requiring antibiotics in the past 12 months.
The urine sensitivity test report is still unavailable. A clean catch urine sample is taken for urine dipstick, which reveals the presence of blood, protein, leukocytes and nitrites. Fresh blood tests were sent, and her estimated GFR is calculated to be 40 ml/minute.
Out of the following, which antibiotic is most appropriate to be prescribed to this patient?Your Answer:
Correct Answer: Trimethoprim
Explanation:The NICE guidelines for children and young people under 16 years lower UTIs are:
1. Get a urine sample before antibiotics are taken, and do a dipstick test OR send for culture and susceptibility
2. Assess and manage children under 5 with lower UTI with fever as recommended in the NICE guideline on fever in under 5s.
3. Prescribe an immediate antibiotic prescription and take into account the previous urine culture and susceptibility results, previous antibiotic use, which may have led to resistant bacteria
4. If urine culture and susceptibility report is sent
– Review the choice of antibiotic when the results are available AND
– change the antibiotic according to susceptibility results if the bacteria are resistant and symptoms are not improving, using a narrow-spectrum antibiotic wherever possibleThe choice of antibiotics for non-pregnant young people under 16 years with lower UTI is summarised below:
1. Children under 3 months:
– Refer to paediatric specialist and treat with intravenous antibiotic in line with NICE guideline on fever in under 5s
2. Children over 3 months:
– First-choice
Nitrofurantoin – if eGFR >45 ml/minute
Trimethoprim – (if low risk of resistance*)
– Second-choice (no improvement in lower UTI symptoms on first-choice for at least 48 hours, or when first-choice not suitable)
Nitrofurantoin – if eGFR >45 ml/minute and not used as first-choice
Amoxicillin (only if culture results available and susceptible)
Cefalexin -
This question is part of the following fields:
- Infections
- Pharmacology
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Question 36
Incorrect
-
You are about to give an antimuscarinic agent to a 55 year-old male patient. Which of the following conditions will make you with stop the administration, since it is a contraindication to antimuscarinic agents?
Your Answer:
Correct Answer: Prostatic enlargement
Explanation:Antimuscarinic medications may impair the contractility of bladder smooth muscle, resulting in acute urine retention in men with BPH, and should be avoided or used with caution.
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This question is part of the following fields:
- Gastrointestinal
- Pharmacology
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Question 37
Incorrect
-
A patient presents with acute severe asthma. Her initial salbutamol nebulization produced a poor response and you administer another nebuliser with ipratropium bromide added on.
Which statement about ipratropium bromide is true?Your Answer:
Correct Answer: It can trigger acute closed-angle glaucoma
Explanation:Ipratropium bromide is an antimuscarinic drug. It is used in the management of acute asthma and COPD.
It provides short-term relief in chronic asthma. Short-acting β2agonists are preferred and act more quickly.
The commonest side effect of ipratropium bromide is dry mouth. Tremor is commonly seen with β2agonists.
It can trigger acute closed-angle glaucoma in patients that are susceptible.
First-line treatment for moderate asthma attacks is short-acting β2agonists.
The BTS guidelines recommend that nebulised ipratropium bromide (0.5 mg 4-6 hourly) be added to β2agonist treatment in patients with a poor initial response to β2agonist therapy or with acute severe or life-threatening asthma.
Its duration of action is 3-6 hours, maximum effect occurs 30-60 minutes after use, and bronchodilation can be maintained with three times per day dosing.
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This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 38
Incorrect
-
Regarding gas exchange at the alveolar-capillary membrane, which of the following statements is CORRECT:
Your Answer:
Correct Answer: Transfer of oxygen is usually perfusion-limited.
Explanation:Gas exchange between alveolar air and blood in the pulmonary capillaries takes place by diffusion across the alveolar-capillary membrane. Diffusion occurs from an area of high partial pressure to an area of low partial pressure, thus the driving force for diffusion is the alveolar-capillary partial pressure gradient. Diffusion occurs until equilibrium is reached, but random movement of particles continues to occur and this is known as dynamic equilibrium. The diffusing capacity for oxygen (DLO2) cannot be measured directly but the rate of diffusion in the lungs can be estimated by measuring the diffusing capacity of the lungs for carbon monoxide (DLCO), not by measuring total lung capacity. The rate of transfer of a gas may be diffusion or perfusion limited; carbon monoxide transfer is diffusion-limited, oxygen transfer is usually perfusion-limited.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 39
Incorrect
-
Which of the following infections is vancomycin most likely prescribed for?
Your Answer:
Correct Answer: Clostridium difficile colitis
Explanation:125 mg PO q6hr for 10 days is indicated for treatment of Clostridium difficile (C. difficile)-associated diarrhoea
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 40
Incorrect
-
Which of the following side effects has limited the use of etomidate as an intravenous induction agent:
Your Answer:
Correct Answer: Adrenocortical suppression
Explanation:Etomidate causes the least cardiovascular depression of the intravenous induction agents, with only a small reduction in the cardiac output and blood pressure. In the past, etomidate was widely used to induce anaesthesia in the shocked, elderly or cardiovascularly unstable patient. However, more recently it has become less popular as a single induction dose blocks the normal stress-induced increase in adrenal cortisol production for 4 – 8 hours, and up to 24 hours in elderly and debilitated patients. Although no increase in mortality has been identified following a single dose during induction of anaesthesia, the use of etomidate has declined due to a perceived potential morbidity.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 41
Incorrect
-
Which of the following is NOT one of insulin's actions:
Your Answer:
Correct Answer: Increased gluconeogenesis
Explanation:Insulin has a number of effects on glucose metabolism, including:
Inhibition of glycogenolysis and gluconeogenesis
Increased glucose transport into fat and muscle
Increased glycolysis in fat and muscle
Stimulation of glycogen synthesis
By inhibiting gluconeogenesis, insulin maintains the availability of amino acids as substrates for protein synthesis. Thus, insulin supports protein synthesis through direct and indirect mechanisms. -
This question is part of the following fields:
- Endocrine
- Pharmacology
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Question 42
Incorrect
-
Which of the following is NOT an effect of benzodiazepines:
Your Answer:
Correct Answer: Analgesic effect
Explanation:Benzodiazepines are gamma-aminobutyric acid (GABA) receptor agonists which enhance inhibitory synaptic transmission throughout the central nervous system, with sedative, hypnotic, anxiolytic, anticonvulsant, amnesic and muscle relaxant properties.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 43
Incorrect
-
Streptococcus viridans has developed subacute bacterial endocarditis in your patient. Which of the following locations is most likely to be the organism's origin?
Your Answer:
Correct Answer: Oral cavity
Explanation:Streptococci that are alpha-haemolytic, such as Streptococcus viridans, are major components of the flora in the oral cavity.
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This question is part of the following fields:
- Infections
- Microbiology
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Question 44
Incorrect
-
Flumazenil is a reversal agent for which of the following groups of drugs:
Your Answer:
Correct Answer: Benzodiazepines
Explanation:Flumazenil is a benzodiazepine antagonist used for the reversal of the sedative effects of benzodiazepines after anaesthesia, sedation and similar procedures.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 45
Incorrect
-
A 78-year-old woman visits the emergency room with dizziness and nausea. She claims that her doctor gave her cinnarizine two days prior, but that it didn't seem to help.
Cinnarizine's mechanism of action is which of the following?Your Answer:
Correct Answer: Antihistamine action
Explanation:Cinnarizine is a piperazine derivative with an antihistamine effect that makes it anti-emetic. Motion sickness and vestibular disorders, such as Méniéres disease, are the most common conditions for which it is prescribed.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 46
Incorrect
-
After collapsing at home, a 62-year-old man is transported in an ambulance. He is now awake, but he is experiencing palpitations and chest pain. He is rushed to resuscitation and placed on a cardiac monitor, which reveals ventricular tachycardia. An amiodarone infusion is set up.
Which of these statements about amiodarone is correct?Your Answer:
Correct Answer: It is expressed in breast milk
Explanation:Antiarrhythmic drug amiodarone is used to treat both ventricular and atrial arrhythmias. It’s a class III antiarrhythmic that works by prolonging the repolarization phase of the cardiac action potential, where potassium permeability is normally high and calcium permeability is low.
Dronedarone is sometimes used instead of amiodarone in certain situations. Although amiodarone is more effective than dronedarone, dronedarone has fewer side effects.
Grapefruit juice inhibits the metabolism of amiodarone.
The plasma half-life of amiodarone is very long, ranging from 2 weeks to 5 months. The half-life is about 2 months on average.
Because amiodarone is excreted in breast milk, it should be avoided by breastfeeding mothers. -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 47
Incorrect
-
Which of the following intravenous induction drugs results in the highest drop in blood pressure:
Your Answer:
Correct Answer: Propofol
Explanation:Propofol’s most frequent side effect is hypotension, which affects 17% of paediatric patients and 26% of adults. This is attributable to systemic vasodilation as well as a decrease in preload and afterload. Propofol has a little negative inotropic impact as well. The drop in blood pressure is dosage-dependent and is more noticeable in the elderly, thus this should be expected.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 48
Incorrect
-
The patient is a 61-year-old man with severe central chest pain. An acute myocardial infarction is revealed by his ECG. Clopidogrel is one of the medications he takes as part of his treatment.
Clopidogrel's direct mechanism of action is which of the following?Your Answer:
Correct Answer: Inhibition of platelet ADP receptors
Explanation:Clopidogrel, a thienopyridine derivative, prevents platelet aggregation and cross-linking by the protein fibrin by inhibiting the ADP receptor on platelet cell membranes (inhibits binding of ADP to its platelet receptor (P2Y12 ADP-receptor).
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 49
Incorrect
-
Which of the following lifestyle changes is not likely to improve symptoms of gastro-oesophageal reflux disease (GORD):
Your Answer:
Correct Answer: Lowering the head of the bed
Explanation:The following approaches have some benefit in adult patients with reflux:
Weight loss or weight management for individuals who are overweight
Head of bed elevation is important for individuals with nocturnal or laryngeal symptoms, but its value for other situations is unclear.
The following lifestyle approaches also are used frequently. There is some evidence that these lifestyle changes improve laboratory measures of reflux (such as lower oesophageal sphincter pressure).
Dietary modification – A practical approach is to avoid a core group of reflux-inducing foods, including chocolate, peppermint, and alcohol, which may reduce lower oesophageal sphincter pressure. Acidic beverages, including colas with caffeine and orange juice also may exacerbate symptoms.
Avoiding the supine position soon after eating.
Promotion of salivation by either chewing gum or using oral lozenges. Salivation neutralizes refluxed acid, thereby increasing the rate of oesophageal acid clearance.
Avoidance of tobacco (including passive exposure to tobacco smoke) and alcohol. Nicotine and alcohol reduce lower oesophageal sphincter pressure, and smoking also diminishes salivation. -
This question is part of the following fields:
- Gastrointestinal
- Pharmacology
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Question 50
Incorrect
-
The functional residual capacity (FRC) will be decreased in which of the following:
Your Answer:
Correct Answer: Pulmonary fibrosis
Explanation:Factors decreasing FRC:
Restrictive ventilatory defects e.g. pulmonary fibrosis
Posture – lying supine
Increased intra-abdominal pressure (e.g. obesity, pregnancy, ascites)
Reduced muscle tone of diaphragm e.g. muscle relaxants in anaesthesia, neuromuscular disease -
This question is part of the following fields:
- Physiology
- Respiratory
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Question 51
Incorrect
-
A 53 year old women presents to the emergency room with a chronic cough. The pulmonary receptors likely to be involved in causing her cough are:
Your Answer:
Correct Answer: Irritant receptors
Explanation:Throughout the airways, there are irritant receptors which are located between epithelial cells which are made of rapidly adapting afferent myelinated fibres in the vagus nerve. A cough is as a result of receptor stimulation located in the trachea, hyperpnoea is as a result of receptor stimulation in the lower airway. Stimulation may also result in reflex bronchial and laryngeal constriction. Many factors can stimulate irritant receptors. These include irritant gases, smoke and dust, airway deformation, pulmonary congestion, rapid inflation/deflation and inflammation. Deep augmented breaths or sighs seen every 5 – 20 minutes at rest are due to stimulation of these irritant receptors. This reverses the slow lung collapse that occurs in quiet breathing.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 52
Incorrect
-
A 58-year-old male has cellulitis of his left leg. Because he is allergic to penicillin, you start him on erythromycin.
What is erythromycin's mechanism of action?Your Answer:
Correct Answer: Inhibition of protein synthesis
Explanation:Bacteriostatic antibiotics include erythromycin and other macrolide antibiotics. They work by attaching to the bacterial ribosome’s 50S subunit, preventing translocation and thereby protein synthesis. Macrolide antibiotics are actively concentrated inside leukocytes and delivered to the infection site as a result.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 53
Incorrect
-
The average BP reading on ambulatory blood pressure monitoring for a 59-year-old Caucasian man is 152/96 mmHg (ABPM).
The first-line drug treatment for this patient would be which of the following? Please only choose ONE answer.Your Answer:
Correct Answer: Amlodipine
Explanation:An ambulatory blood pressure reading of >150/95 is classified as stage 2 hypertension, according to the NICE care pathway for hypertension, and the patient should be treated with an antihypertensive drug.
A calcium-channel blocker, such as amlodipine, would be the most appropriate medication for a 59-year-old Caucasian man.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 54
Incorrect
-
The following all cause a right shift in the oxygen dissociation curve EXCEPT for:
Your Answer:
Correct Answer: Foetal haemoglobin
Explanation:A decreased affinity of haemoglobin for oxygen (and hence increased ease of dissociation), shown by a right shift in the oxygen dissociation curve, is caused by a fall in pH, a rise in PCO2(the Bohr effect) and an increase in temperature. These changes occur in metabolically active tissues such as in exercise, and encourage oxygen release. The metabolic by-product 2,3-diphosphoglycerate (2,3 -DPG) also causes a right shift; 2, 3 -DPG may also be raised in chronic anaemia, chronic lung disease, or at high altitude. Foetal haemoglobin (HbF) binds 2, 3 -DPG less strongly than does adult haemoglobin (HbA), and so the HbF dissociation curve lies to the left of that for HbA, reflecting its higher oxygen affinity. This helps transfer oxygen from mother to foetus.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 55
Incorrect
-
Which of the following antibiotics may be used for malaria prophylaxis:
Your Answer:
Correct Answer: Doxycycline
Explanation:Doxycycline may be used for malaria prophylaxis and as an adjunct to quinine in the treatment of Plasmodium falciparum malaria.
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This question is part of the following fields:
- Infections
- Pharmacology
-
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Question 56
Incorrect
-
A patient presents with an acute severe asthma attack. Following a poor response to his initial salbutamol nebuliser, you administer a further nebuliser that this time also contains ipratropium bromide.
After what time period would you expect the maximum effect of the ipratropium bromide to occur? Select ONE answer only.Your Answer:
Correct Answer: 30 -60 minutes
Explanation:Ipratropium bromide is an antimuscarinic drug used in the management of acute asthma and COPD. It can provide short-term relief in chronic asthma, but short-acting β2agonists act more quickly and are preferred.
The BTS guidelines recommend that nebulised ipratropium bromide (0.5 mg 4-6 hourly) can be added to β2agonist treatment for patients with acute severe or life-threatening asthma or those with a poor initial response to β2 agonist therapy.
The aerosol inhalation of ipratropium can be used for short-term relief in mild chronic obstructive pulmonary disease in patients who are not already using a long-acting antimuscarinic drug (e.g. tiotropium).Its maximum effect occurs 30-60 minutes after use; its duration of action is 3-6 hours, and bronchodilation can usually be maintained with treatment three times per day.
The commonest side effect of ipratropium bromide is dry mouth. It can also trigger acute closed-angle glaucoma in susceptible patients. Tremor is commonly seen with β2agonists but not with antimuscarinics. Ipratropium bromide should be used with caution in: Men with prostatic hyperplasia and bladder-outflow obstruction (worsened urinary retention has been reported in elderly men), People with chronic kidney disease (CKD) stages 3 and above (because of the risk of drug toxicity), People with angle-closure glaucoma (nebulised mist of antimuscarinic drugs can precipitate or worsen acute angle-closure glaucoma) -
This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 57
Incorrect
-
Question 58
Incorrect
-
A patient allergic to penicillin and with marked cellulitis presents and you decide to start him on erythromycin.
Which statement about macrolide antibiotics is true?
Your Answer:
Correct Answer: They are actively concentrated within leukocytes
Explanation:Macrolide antibiotics are bacteriostatic.
They act by binding to the 50S subunit of the bacterial ribosome inhibit protein synthesis.
Macrolide antibiotics are actively concentrated within leukocytes, because of this, they are transported into the site of infection.
Macrolide antibiotics are not effective in meningitis as they do not penetrate the central nervous system well.
They are mainly against Gram-positive organisms and can be used as an alternative in patients with penicillin allergy.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 59
Incorrect
-
A 22-year-old woman is brought in by ambulance from her GP surgery with suspected meningitis. She has been given a dose of benzylpenicillin already.
What is the mechanism of action of benzylpenicillin? Select ONE answer only.Your Answer:
Correct Answer: Inhibition of cell wall synthesis
Explanation:Penicillins and the other ß-lactam antibiotics are bactericidal. They produce their antimicrobial action by preventing cross-linkage between the linear peptidoglycan polymer chains that make up the bacterial cell wall. They, therefore, inhibit cell wall synthesis.
An overview of the different mechanisms of action of the various types of antimicrobial agents is shown below:
Mechanism of action
Examples
Inhibition of cell wall synthesis
Penicillins
Cephalosporins
Vancomycin
Disruption of cell membrane function
Polymyxins
Nystatin
Amphotericin B
Inhibition of protein synthesis
Macrolides
Aminoglycosides
Tetracyclines
Chloramphenicol
Inhibition of nucleic acid synthesis
Quinolones
Trimethoprim
5-nitroimidazoles
Rifampicin
Anti-metabolic activity
Sulfonamides
Isoniazid -
This question is part of the following fields:
- Infections
- Pharmacology
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Question 60
Incorrect
-
A 22-year-old man comes to the emergency department with a human bite injury to his hand received from a punch during a fight 3 hours earlier outside a bar. On closer inspection, you discover bite marks on his first and second knuckles. Which of the following is the best treatment option for this patient:
Your Answer:
Correct Answer: Oral co-amoxiclav for 7 days
Explanation:Even if there is no evidence of infection, prophylactic antibiotics should be administered for all human bite wounds that are less than 72 hours old. The first-line therapy is 7 days of co-amoxiclav. In penicillin-allergic people, metronidazole + doxycycline is an option. Streptococcus spp., Staphylococcus aureus, Haemophilus spp., Eikenella corrodens, Bacteroides spp., and other anaerobes are the most prevalent organisms found in human bites.
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This question is part of the following fields:
- Infections
- Microbiology
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Question 61
Incorrect
-
You're examining a 58-year-old male who has cellulitis in his left leg. Because he is allergic to penicillin, you start him on erythromycin.
Which of the following statements about erythromycin is correct?Your Answer:
Correct Answer: It can be used to treat Legionnaire’s disease
Explanation:Bacteriostatic antibiotics include erythromycin and other macrolide antibiotics. They work by attaching to the bacterial ribosome’s 50S subunit, preventing translocation and thereby protein synthesis. Macrolide antibiotics are actively concentrated inside leukocytes and delivered to the infection site as a result.
Erythromycin is an orally active antibiotic that can also be given intravenously. It is metabolized in the liver and eliminated in the bile and has a biological half-life of 1.5 hours.
It has a similar antibacterial spectrum to benzylpenicillin (i.e., a narrow spectrum, primarily against Gram-positive pathogens) and can be used as a penicillin substitute in people who are allergic to penicillin.
Erythromycin is unsuccessful in the treatment of meningitis because it does not penetrate the central nervous system well enough. It is efficient against a variety of unusual pathogens, unlike penicillin. -
This question is part of the following fields:
- Infections
- Pharmacology
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Question 62
Incorrect
-
A 59-year-old man presents to the emergency room with chest pain. The cardiology team recently discharged him. He underwent a procedure and was given several medications, including abciximab, during his stay. Which of the following statements about abciximab is correct?
Your Answer:
Correct Answer: It is a glycoprotein IIa/IIIb receptor antagonist
Explanation:Abciximab (ReoPro) is a glycoprotein IIb/IIIa receptor antagonist that is a chimeric monoclonal antibody. It is primarily used during and after coronary artery procedures such as angioplasty to inhibit platelet aggregation.
It’s approved for use as a supplement to heparin and aspirin in high-risk patients undergoing percutaneous transluminal coronary intervention to prevent ischaemic complications. Only one dose of abciximab should be given (to avoid additional risk of thrombocytopenia).
Before using, it is recommended that baseline prothrombin time, activated clotting time, activated partial thromboplastin time, platelet count, haemoglobin, and haematocrit be measured. 12 and 24 hours after starting treatment, haemoglobin and haematocrit should be measured again, as should platelet count 2-4 hours and 24 hours after starting treatment.
When used for high-risk patients undergoing angioplasty, the EPIC trial(link is external)found that abciximab reduced the risk of death, myocardial infarction, repeat angioplasty, bypass surgery, and balloon pump insertion.The use of abciximab is contraindicated in the following situations:
Internal bleeding is present.
Within the last two months, you’ve had major surgery, intracranial surgery, or trauma.
Stroke in the previous two years
Intracranial tumour
Aneurysm or arteriovenous malformation
Haemorrhagic diathesis is a type of haemorrhagic diathesis.
Vasculitis
Retinopathy caused by hypertensionThe following are some of the most common abciximab side effects:
Manifestations of bleeding
Bradycardia
Back ache
Pain in the chest
Vomiting and nausea
Pain at the puncture site
Thrombocytopenia -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 63
Incorrect
-
Regarding aciclovir, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: Aciclovir eradicates herpes simplex virus from the body.
Explanation:Aciclovir is active against herpesviruses but does not eradicate latent virus.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 64
Incorrect
-
A young 20-year-old boy is a known case of type I diabetes mellitus. Today, he presents with polyuria, polydipsia, and abdominal pain in the emergency department. His blood sugar is drawn, which is markedly elevated to 7 mmol/L. Quick ABGs are drawn, which show metabolic acidosis. You diagnose the patient to be suffering from diabetic ketoacidosis (DKA) and immediately commence its treatment protocol in which insulin is also administered.
Out of the following, which parameter is MOST likely to change due to initiating insulin?Your Answer:
Correct Answer: Potassium
Explanation:Diabetes ketoacidosis is an acute complication of diabetes mellitus. Insulin is administered to achieve euglycemia, and crystalloids or colloidal solution is administered to achieve euvolemia and euelectrolytaemia.
Potassium levels severely fluctuate during the treatment of DKA, hypokalaemia being more common. Insulin promotes the cell to take up potassium from the extracellular space via increased sodium-potassium pump activity.
It is important to monitor potassium levels during the treatment of DKA regularly. It is widely suggested that the normal saline shall be used for initial resuscitation, and once the potassium level is retrieved, the patient can be started on potassium replacement should the serum potassium level be between 3.3 and 4.5 mmol/L
If potassium levels fall below 3.3 mmol/l, insulin administration may need to be interrupted to correct the hypokalaemia. -
This question is part of the following fields:
- Endocrine Pharmacology
- Pharmacology
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Question 65
Incorrect
-
A 23-year-old student presents to the emergency department with a terrible headache, photophobia, and a fever. On her lower limbs, you see a non-blanching purpuric rash. In the department, a lumbar puncture is conducted. What do you think you'll notice on Gram stain:
Your Answer:
Correct Answer: Gram negative diplococci
Explanation:Bacterial meningitis and septicaemia are most commonly caused by meningococcal bacteria. The Gram-negative diplococci Neisseria Meningitidis causes meningitis. Gram stain and culture of CSF identify the etiologic organism, N meningitidis. In bacterial meningitis, Gram stain is positive in 70-90% of untreated cases, and culture results are positive in as many as 80% of cases.
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This question is part of the following fields:
- Infections
- Microbiology
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Question 66
Incorrect
-
Regarding chemical control of respiration, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: The blood-brain barrier is freely permeable to HCO3 - ions.
Explanation:CSF is separated from the blood by the blood-brain barrier. This barrier is impermeable to polar molecules such as H+and HCO3-but CO2can diffuse across it easily. The pH of CSF is therefore determined by the arterial PCO2and the CSF HCO3-and is not affected by blood pH.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 67
Incorrect
-
You've been summoned to a young man in the resus area who has an SVT. You decide to use adenosine after trying several vagal manoeuvres without success.
The use of adenosine is not contraindicated in which of the following situations?Your Answer:
Correct Answer: Concurrent use of a beta-blocker
Explanation:The use of a beta-blocker at the same time increases the risk of myocardial depression, but it is not a contraindication.
The use of adenosine is contraindicated in the following situations:
Asthma
COPD (chronic obstructive pulmonary disease)
Decompensated heart failure
Long QT syndrome
AV block in the second or third degree
Sinusitis is a condition in which the sinuses become (unless pacemaker fitted)
Hypotension that is severe -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 68
Incorrect
-
A 32-old woman comes for a follow-up visit after being discharged on medications for her newly diagnosed epilepsy. She now complains of a tremor in her arm when she holds a tray in her hand. You examine the patient and notice she has developed postural tremors.
Which of the following medications for epilepsy is most likely responsible for this tremor?Your Answer:
Correct Answer: Sodium valproate
Explanation:A postural tumour is observed when a person maintains a position against gravity, such as holding the arms outstretched. (The patient holding her tray against gravity)
Sodium valproate is the most commonly prescribed medication for epilepsy. It is commonly associated with tremors as valproate-induced tremors occur in around 6-45% of patients. The tremors are commonly postural, but a resting tremor may also occur.
Approximately 25% of patients taking sodium valproate are found to develop a tremor within 3-12 months of initiating therapy.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 69
Incorrect
-
A 66-year-old female who is a known case of atrial fibrillation comes to the Emergency Department with the complaint of fever and vomiting for the past two days. When her medical chart is reviewed, you see that she takes Warfarin for her arrhythmia.
Which ONE of the following medications cannot be prescribed to this patient?Your Answer:
Correct Answer: Ibuprofen
Explanation:Like other non-steroidal anti-inflammatory drugs, Ibuprofen cannot be given with Warfarin as it would increase the bleeding risk of this patient.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 70
Incorrect
-
You're currently treating an infection in a patient and trying to figure out which antibiotic would be best.
Which of the following antimicrobial drugs inhibits the formation of cell walls?Your Answer:
Correct Answer: Cefuroxime
Explanation:Cefuroxime and other cephalosporin antibiotics are bactericidal ß-lactam antibiotics. They work similarly to penicillins in that they prevent cross-linking between the linear peptidoglycan polymer chains that make up the bacterial cell wall. As a result, they prevent the formation of cell walls.
The following is a summary of the various mechanisms of action of various types of antimicrobial agents:1) Inhibition of cell wall synthesis
Penicillins
Cephalosporins
Vancomycin2) Disruption of cell membrane function
Polymyxins
Nystatin
Amphotericin B3) Inhibition of protein synthesis
Macrolides
Aminoglycosides
Tetracyclines
Chloramphenicol4) Inhibition of nucleic acid synthesis
Quinolones
Trimethoprim
5-nitroimidazoles
Rifampicin5) Anti-metabolic activity
Sulphonamides
Isoniazid -
This question is part of the following fields:
- Infections
- Pharmacology
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Question 71
Incorrect
-
Hartmann's solution contains how much sodium:
Your Answer:
Correct Answer: 131 mmol/L
Explanation:Hartmann’s solution (compound sodium lactate) contains: Na+131 mmol/L, K+5 mmol/L, HCO3-29 mmol/L (as lactate), Cl-111 mmol/L, Ca2+2 mmol/L. It can be used instead of isotonic sodium chloride solution during or after surgery, or in the initial management of the injured or wounded; it may reduce the risk of hyperchloraemic acidosis.
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This question is part of the following fields:
- Fluids And Electrolytes
- Pharmacology
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Question 72
Incorrect
-
A 50-year-old man has recently been on antibiotics for a chest infection. He suffers from COPD and is currently on Seretide inhalers, salbutamol, and Phyllocontin continus. Since commencing the antibiotics, he has developed nausea, vomiting and abdominal pain.
Which of the following antibiotics has he MOST LIKELY been on for his chest infection?Your Answer:
Correct Answer: Erythromycin
Explanation:Phyllocontin continues contains aminophylline, a bronchodilator used in the management of asthma and COPD.
The index patient is exhibiting symptoms of theophylline toxicity. This may have been triggered by the antibiotic he took. Macrolide antibiotics, like erythromycin and quinolone antibiotics, like ciprofloxacin and levofloxacin, increases the plasma concentration of theophyllines and can lead to toxicity.
Factors that enhance theophylline clearance include cigarette smoking, carbamazepine, phenobarbital, phenytoin, primidone, and rifampin.
Medications that inhibit clearance include ethanol, ciprofloxacin, erythromycin, verapamil, propranolol, ticlopidine, tacrine, allopurinol, and cimetidine. -
This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 73
Incorrect
-
A 25-year-old female arrives at the emergency room with a severe case of asthma. When she doesn't seem to be improving after initial treatment, you decide to start an aminophylline infusion.
From the options below, which is Aminophylline's main mechanism of action?Your Answer:
Correct Answer: Phosphodiesterase inhibition
Explanation:Theophylline and Ethylenediamine are combined in a 2:1 ratio to form Aminophylline. Its solubility is improved by the addition of Ethylenediamine. It has a lower potency and a shorter duration of action than Theophylline.
It is used to treat the following conditions:
Heart failure
It is used to treat the following conditions:
COPD
BradycardiasAminophylline has the following properties:
Phosphodiesterase inhibitor that increases intracellular cAMP and relaxes smooth muscle in the bronchial airways and pulmonary blood vessels.
Mast cell stabilization is achieved by using a non-selective adenosine receptor antagonist.
It has slight positive inotropic and chronotropic effects, increasing cardiac output and decreasing systemic vascular resistance, lowering arterial blood pressure. It has been used historically in the treatment of refractory heart failure and is indicated by the current ALS guidelines as a substitute treatment for bradycardia.The daily oral dose for adults is 900 mg, divided into 2-3 doses. For severe asthma or COPD, a loading dosage of 5 mg/kg over 10-20 minutes is given, followed by a continuous infusion of 0.5 mg/kg/hour. The therapeutic range is small (10-20 microgram/ml), hence assessments of aminophylline plasma concentrations are useful during long-term treatment.
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This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 74
Incorrect
-
A 33 year old female patient presents to emergency room with some symptoms that she thinks might be due to a drug that she has recently started. She was started on hyoscine butyl bromide for symptomatic relief of irritable bowel syndrome. The least likely expected side effect of this drug in this patient is:
Your Answer:
Correct Answer: Diarrhoea
Explanation:One of the commonest antispasmodic medications that is used is hyoscine butylbromide. It is an antimuscarinic and typical side effects of this class of drugs include:
– dilation of pupils with loss of accommodation (cycloplegia)
-photophobia resulting in blurred vision (Blind as a bat)
-dry mouth, eyes and skin (Dry as a bone),
-elevated temperature (Hot as a hare)
-skin flushing (Red as a beet)
-confusion or agitation particularly in the elderly (Mad as a hatter)
-reduced bronchial secretions
-transient bradycardia followed by tachycardia, palpitation and arrhythmias
-urinary retention and/or constipation -
This question is part of the following fields:
- Gastrointestinal
- Pharmacology
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Question 75
Incorrect
-
Regarding macrolide antibiotics, which of the following statements is CORRECT:
Your Answer:
Correct Answer: Macrolides are first line for treatment of whooping cough.
Explanation:A macrolide antibiotic is recommended first line for whooping cough (if onset of cough is within the previous 21 days)
Prescribe clarithromycin for infants less than 1 month of age.
Prescribe azithromycin or clarithromycin for children aged 1 month or older, and non-pregnant adults.
Prescribe erythromycin for pregnant women.
Macrolides interfere with bacterial protein synthesis and are mainly active against Gram-positive organisms. They have a similar antibacterial spectrum to penicillin and are thus a useful alternative in penicillin-allergic patients. Erythromycin is commonly associated with gastrointestinal upset. -
This question is part of the following fields:
- Infections
- Pharmacology
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Question 76
Incorrect
-
All of the following statements are correct regarding penicillin antibiotics except:
Your Answer:
Correct Answer: Penicillins are of no use in meningitis as they are unable to penetrate into the cerebrospinal fluid.
Explanation:Penicillin penetration into the cerebrospinal fluid is generally poor. However, when the meninges are inflamed, as in meningitis, penetration of penicillin is increased. Benzylpenicillin should be given before transfer to hospital if meningococcal disease (meningitis with non-blanching rash or meningococcal septicaemia) is suspected, once this does not delay transfer.
Benzylpenicillin is no longer the drug of first choice for pneumococcal meningitis.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 77
Incorrect
-
Atracurium is used as a muscle relaxant during endotracheal intubation. This drug’s mechanism of action is best described by which of the following?
Your Answer:
Correct Answer: Nicotinic acetylcholine receptor antagonist
Explanation:Atracurium is a non-depolarizing neuromuscular blocker that is used to help with intubation and controlled ventilation by causing muscle relaxation and paralysis.
At the neuromuscular junction’s post-synaptic membrane, atracurium competes with acetylcholine for nicotinic (N2) receptor binding sites. This prevents the receptors from being stimulated by acetylcholine.
Muscle paralysis occurs gradually due to the competitive blockade.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 78
Incorrect
-
You want to give colchicine to a patient who has acute gout. Which of the following is a contraindication to the use of colchicine?
Your Answer:
Correct Answer: Blood dyscrasias
Explanation:Colchicine is used to prevent or treat gout attacks (flares). It works by reducing swelling and the development of uric acid crystals, which cause pain in the affected joint(s).
Colchicine should be avoided by patients who have blood dyscrasias or bone marrow disorders.
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This question is part of the following fields:
- Musculoskeletal
- Pharmacology
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Question 79
Incorrect
-
An unrelated medical condition brings a 28-year-old asthmatic man to the Emergency Department. When you look over his meds, you notice that he is taking Theophylline to help with his asthma.
Which of the following medicines should you NOT prescribe?Your Answer:
Correct Answer: Ciprofloxacin
Explanation:Ciprofloxacin is a cytochrome P450 enzyme inhibitor that raises theophylline levels in the blood. As a result, co-prescribing theophylline should be avoided.
The medicines that typically impact theophylline’s half-life and plasma concentration are listed in the table below:
Drugs that increase the levels of theophylline in the blood
Drugs that lower theophylline levels in the blood
Calcium channel blockers e.g. Verapamil
Fluconazole
Cimetidine
Quinolones, e.g. ciprofloxacin
Methotrexate
Barbiturates
Carbamazepine
Phenobarbital
Macrolides, e.g. erythromycin
Phenytoin (and fosphenytoin)
Rifampicin
St. John’s wort -
This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 80
Incorrect
-
You examine a 43-year-old woman who was referred to you by a friend. She suffers from a variety of medical conditions and takes a variety of medications, including amitriptyline.
Which of the following is NOT a contraindication to amitriptyline treatment?Your Answer:
Correct Answer: Breastfeeding
Explanation:Amitriptyline is a tricyclic antidepressant (TCA) that is most commonly used to treat depression, but it can also be used to treat anxiety disorders, chronic pain, and attention deficit hyperactivity disorder (ADHD). It inhibits reuptake, raising serotonin and noradrenaline levels while also inhibiting acetylcholine action.
TCAs have a number of drawbacks, including:
Acute Porphyria
Arrhythmias
During bipolar disorder’s manic phase
Heart block
After a myocardial infarction, there is an immediate recovery period.TCA levels in breast milk are too low to be harmful, and use can be continued while breastfeeding.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 81
Incorrect
-
A patient is currently taking is glyceryl trinitrate among other chronic medications. Which of the following side effects is he LEAST likely to develop?
Your Answer:
Correct Answer: Syncope
Explanation:Nitrates are used in the treatment of angina pectoris and the prevention of myocardial ischaemia. Commonly used examples of nitrates are glyceryl trinitrate and isosorbide dinitrate. Unwanted effects, however, are common and can limit therapy, particularly when angina is severe or when patients are unusually sensitive to the effects of nitrates.
The following are common or very common side effects of nitrates:
- Arrhythmias
- Asthenia
- Cerebral ischaemia
- Dizziness
- Drowsiness
- Flushing
- Headache
- Hypotension
- Nausea and vomiting
- Diarrhoea, syncope and cyanosis can occur, but these are rare side effects.
Dry eyes, bradycardia and metabolic acidosis have not been reported.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 82
Incorrect
-
A young pregnant woman is in the late stages of her pregnancy. She is administered a drug that results in her newborn being born with respiratory depression. The baby also suffers from neonatal withdrawal syndrome.
Out of the following, which drug is most likely responsible for the baby's condition?Your Answer:
Correct Answer: Diazepam
Explanation:Benzodiazepines are used as a first-line treatment in breaking seizures and in status epilepticus as they are rapid-acting.
Use of benzodiazepines in the late third-trimester or exposure during labour is associated with great risks to the foetus/neonate. Babies can exhibit either floppy infant syndrome, or marked neonatal withdrawal symptoms. Symptoms vary from mild sedation, hypotonia, and reluctance to suck, to apnoeic spells, cyanosis, and impaired metabolic responses to cold stress. These symptoms have been reported to persist for periods from hours to months after birth.
They also cross into breast milk and should be used with caution in breastfeeding mothers
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 83
Incorrect
-
You've been summoned to a young man in the resus area who is experiencing an SVT. You decide to use adenosine after trying several vagal manoeuvres without success.
Which of the following is the correct adenosine mechanism of action?Your Answer:
Correct Answer: Opens K + channels in the heart
Explanation:The purine nucleoside adenosine is used to diagnose and treat paroxysmal supraventricular tachycardia. Adenosine works by stimulating A1-adenosine receptors and opening potassium channels that are sensitive to acetylcholine. This causes the atrioventricular (AV) node’s cell membrane to become hyperpolarized, slowing conduction by inhibiting calcium channels.
Patients who have had a heart transplant are extremely sensitive to the effects of adenosine and should start with a lower dose of 3 mg, then 6 mg, and finally 12 mg.Dipyridamole potentiates the effects of adenosine, so it should be used with caution in patients who are taking it.
The use of adenosine is contraindicated in the following situations:
Asthma
COPD (chronic obstructive pulmonary disease)
Decompensated heart failure
Long QT syndrome
AV block in the second or third degree
Sinusitis is a condition in which the sinuses become (unless pacemaker fitted)
Hypotension that is severe -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 84
Incorrect
-
A young male has presented to the Emergency Department with a sudden onset of severe palpitations, shortness of breath, and chest pain. A 12-lead ECG is recorded, and it shows a narrow complex tachycardia that points to a diagnosis of supraventricular tachycardia.
Vagal manoeuvres are attempted but are unsuccessful in eliminating the arrhythmia. The next action plan is to use a drug to revert to sinus rhythm.
Out of the following, which is the first-line treatment for supraventricular tachycardia?Your Answer:
Correct Answer: Adenosine
Explanation:Paroxysmal supraventricular tachycardia is an intermittent tachycardia (HR > 100 bpm) and has the following characteristics:
1. Sudden onset/offset (Contrast with sinus tachycardia)
2. Electrical activity originates above the ventricle (Contrast with ventricular tachycardia)
3. Produces narrow QRS complex (<120ms) The most common cause of PSVT is Atrioventricular nodal re-entrant tachycardia (AVNRT), most common in young women with a mean age onset of 32 years old. There are recurrent episodes of palpitations, and most of the episodes spontaneously. Sometimes, some vagal manoeuvres are required:
1. Valsalva manoeuvre
2. immersing the face in ice-cold water
3. carotid sinus massage.If PSVT keeps persisting or is causing severe symptoms, the treatment of choice is intravenous adenosine. The patient’s ECG should be continuously monitored throughout the treatment.
The recommended doses in adults are as follows:
– Initial dose of adenosine is 6 mg by rapid IV bolus
– If unsuccessful, give another dose of adenosine 12 mg by rapid IV bolus
– If unsuccessful, give a further dose of adenosine 12 mg by rapid IV bolus
The latest ALS guidelines advocate 18 mg for the third dose, whereas the BNF/NICE guidelines advocate 12 mg.If adenosine fails or is contraindicated, intravenous verapamil can be used as an alternative, but it should be avoided in patients recently treated with beta-blockers.
Synchronized electrical cardioversion will be necessary with signs of hemodynamic instability or if drug treatment has failed to restore sinus rhythm.
Recurrent episodes of paroxysmal supraventricular tachycardia can be treated by catheter ablation or prevented with drugs such as flecainide, sotalol, diltiazem, or verapamil. -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 85
Incorrect
-
Regarding propofol, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: A lower induction dose of propofol is required in children.
Explanation:Elderly patients have a reduced volume of distribution and slower clearance of the drug. They are therefore more sensitive to the effects of propofol and the drug wears off more slowly. They need less of the drug, which should be injected slowly, monitoring its effect on the patient. The opposite is true in children, who need larger doses of propofol. This is particularly so in children under three years of age. Propofol is not recommended for induction of anaesthesia in children under one month of age or for maintenance of anaesthesia in children under three years old.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 86
Incorrect
-
A 45-year-old man, a known case of epilepsy, visits his neurologist with complaints of red, swollen gums.
Which of the following medications is most likely responsible for his symptoms?Your Answer:
Correct Answer: Phenytoin
Explanation:Phenytoin is a commonly used antiepileptic drug. A well-recognized side-effect of phenytoin is gingival enlargement and occurs in about 50% of patients receiving phenytoin. It is believed that reduced folate levels may cause this, and evidence suggests that folic acid supplementation may help prevent this in patients starting phenytoin.
As evidence suggests, drug-induced gingival enlargement may also improve by substituting with other anticonvulsant drugs and reinforcing a good oral hygiene regimen. Surgical excision of hyperplastic gingiva is often necessary to correct the aesthetic and functional impairment associated with this condition to manage it successfully.
Phenytoin is also the only anticonvulsant therapy associated with the development of Dupuytren’s contracture.
Other side effects are:
1. Ataxia
2. Drug-induced lupus
3. Hirsutism
4. Pruritic rash
5. Megaloblastic anaemia
6. Nystagmus -
This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 87
Incorrect
-
The functional residual capacity (FRC) will be increased in which of the following:
Your Answer:
Correct Answer: Emphysema
Explanation:Factors increasing FRC:
Emphysema
Air trapping in asthma
Ageing (due to loss of elastic properties)
Increasing height of patient -
This question is part of the following fields:
- Physiology
- Respiratory
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Question 88
Incorrect
-
You examine a 48-year-old woman's blood results and notice that her glucose level is elevated. When you tell her about it, she tells you that her doctor recently ran some tests and discovered that she has impaired glucose tolerance.
Which of the following medications has not been linked to a reduction in glucose tolerance?Your Answer:
Correct Answer: Amlodipine
Explanation:The following drugs have been linked to impaired glucose tolerance:
Thiazide diuretics, e.g. Bendroflumethiazide
Loop diuretics, e.g. furosemide
Steroids, e.g. prednisolone
Beta-blockers, e.g. atenolol -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 89
Incorrect
-
A 32-year-old female is diagnosed case of bipolar disorder and is on medication. She presents to her psychiatric team with symptoms of severe depression. She is currently taking Lithium.
Out of the following, which is TRUE regarding lithium?Your Answer:
Correct Answer: It commonly causes a tremor
Explanation:Lithium is the drug of choice for bipolar disorders but is commonly associated with side effects and toxicity.
Fine hand tremor is very commonly seen and reported in as many as 50% of patients during the first week of therapy with Lithium. The tremor tends to reduce with time and is only present in around 5% of patients taking the medication two years or longer. Lithium tremors are more common with older age, presumably due to the additive effects of age-related essential tremors.
Option The normal therapeutic range is 2.0-2.5 mmol/l: Lithium should be carefully monitored as it has a very low therapeutic index. The normal therapeutic range is 0.4-0.8 mmol/l. Levels should be checked one week after starting therapy and one week after every change in dosage. (Option Levels should be checked one month after starting therapy)
Option It can induce hyperthyroidism: Lithium has a known effect on thyroid function. Lithium decreases the production of T4 and T3 and commonly causes hypothyroidism. More rarely, lithium causes hyperthyroidism due to thyroiditis.
Option It can induce diabetes mellitus: Lithium can induce nephrogenic diabetes insipidus but not diabetes mellitus.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 90
Incorrect
-
Regarding local anaesthetics, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: Adrenaline should be used in digital nerve blocks to create a bloodless field.
Explanation:It is not advisable to give adrenaline/epinephrine with a local anaesthetic injection in digits or appendages because of the risk of ischaemic necrosis.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 91
Incorrect
-
A 58-year-old man with a long history of poorly controlled hypertension complains of a headache and vision blurring today. In triage, his blood pressure is 210/192 mmHg. A CT head scan is scheduled to rule out the possibility of an intracranial haemorrhage. You make the diagnosis of hypertensive encephalopathy and rush the patient to reus to begin blood pressure-lowering treatment. He has a history of brittle asthma, for which he has been admitted to the hospital twice in the last year.
Which of the following is the patient's preferred drug treatment?Your Answer:
Correct Answer: Nicardipine
Explanation:End-organ damage (e.g. encephalopathy, intracranial haemorrhage, acute myocardial infarction or ischaemia, dissection, pulmonary oedema, nephropathy, eclampsia, papilledema, and/or angiopathic haemolytic anaemia) characterises a hypertensive emergency (also known as ‘accelerated hypertension’ or malignant hypertension’ It’s a life-threatening condition that necessitates rapid blood pressure reduction to avoid end-organ damage and a negative outcome.
Hypertensive encephalopathy is a syndrome that includes headaches, seizures, visual changes, and other neurologic symptoms in people who have high blood pressure. It is reversible if treated quickly, but it can progress to coma and death if not treated properly.
Any patient with suspected hypertensive encephalopathy should have an urgent CT scan to rule out an intracranial haemorrhage, as rapid blood pressure reduction could be dangerous in these circumstances.
The drug of choice is labetalol, which reduces blood pressure steadily and consistently without compromising cerebral blood flow.
An initial reduction of approximately 25% in mean arterial pressure (MAP) over an hour should be aimed for, followed by a further controlled MAP reduction over the next 24 hours. In patients who are unable to take beta-blockers, nicardipine can be used as a substitute. -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 92
Incorrect
-
Which of the following local anaesthetics has the longest duration of action:
Your Answer:
Correct Answer: Bupivacaine
Explanation:Bupivacaine has a longer duration of action than the other local anaesthetics, up to 8 hours when used for nerve blocks. It has a slow onset, taking up to 30 minutes for full effect. It is often used in lumbar epidural blockade and is particularly suitable for continuous epidural analgesia in labour, or for postoperative pain relief. It is the principal drug used for spinal anaesthesia.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 93
Incorrect
-
A patient presents to ED with heartburn for which they already take regular antacids. Which of the following drugs can be affected if taken with antacids:
Your Answer:
Correct Answer: Digoxin
Explanation:Antacids should preferably not be taken at the same time as other drugs since they may affect absorption. When antacids are taken with acidic drugs (e.g. digoxin, phenytoin, chlorpromazine, isoniazid) they cause the absorption of the acidic drugs to be decreased, which causes low blood concentrations of the drugs, which ultimately results in reduced effects of the drugs. Antacids taken with drugs such as pseudoephedrine and levodopa increase absorption of the drugs and can cause toxicity/adverse events due to increased blood levels of the drugs. Antacids that contain magnesium trisilicate and magnesium hydroxide when taken with some other medications (such as tetracycline) will bind to the drugs, and reduce their absorption and effects.
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This question is part of the following fields:
- Gastrointestinal
- Pharmacology
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Question 94
Incorrect
-
Doxycycline is indicated first line for treatment of which of the following infections:
Your Answer:
Correct Answer: Chlamydia
Explanation:Doxycycline may be used first line for chlamydia, pelvic inflammatory disease (with metronidazole and ceftriaxone), acute bacterial sinusitis, exacerbation of chronic bronchitis, moderate-severity community acquired pneumonia and high-severity community acquired pneumonia (with benzylpenicillin).
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 95
Incorrect
-
An ambulance transports a 23-year-old woman who has taken a witnessed overdose of her mother's diazepam tablets. She has no significant medical history and does not take any medications on a regular basis.
In this case, what is the SINGLE MOST APPROPRIATE FIRST DRUG TREATMENT?Your Answer:
Correct Answer: Flumazenil IV 200 μg
Explanation:Flumazenil is a benzodiazepine antagonist that can be helpful in some overdose situations. It works quickly (in less than a minute), but the effects are fleeting, lasting less than an hour. The dose is 200 micrograms every 1-2 minutes with a maximum dose of 3 milligrams per hour.
Flumazenil should be avoided by patients who are addicted to benzodiazepines or who take tricyclic antidepressants because it can cause withdrawal symptoms. It can cause seizures or cardiac arrest in these situations.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 96
Incorrect
-
Which of the following is NOT a common effect of etomidate:
Your Answer:
Correct Answer: Significant hypotension
Explanation:Etomidate causes less hypotension than thiopental sodium and propofol during induction. However, it is associated with a high incidence of extraneous muscle movements, which can be minimised by an opioid analgesic or a short-acting benzodiazepine given prior to induction. Pain on injection is common and there is a high rate of thrombophlebitis in the postoperative period. Postoperative nausea and vomiting commonly occur. Etomidate suppresses adrenocortical function, particularly during continuous administration, and it should not be used for maintenance of anaesthesia. It should be used with caution in patients with underlying adrenal insufficiency, for example, those with sepsis.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 97
Incorrect
-
You review a patient with urinary sepsis and decide to start her on gentamicin.
Which statement about gentamicin is true?
Your Answer:
Correct Answer: Ototoxicity is a dose-related effect
Explanation:Gentamicin, an aminoglycoside antibiotic, acts by binding to the 30S subunit of the bacterial ribosome inhibiting the binding of aminoacyl-tRNA, and thus prevents initiation of protein synthesis.
Gentamicin is given by injection because it is NOT absorbed orally.
It is excreted in the kidneys by glomerular filtration
Gentamicin is not to be used for the treatment of Neisseria meningitidis, Neisseria gonorrhoea, or Legionella pneumophila.There is a risk of patient going into shock from lipid A endotoxin release.
Two of its most notable side effects are hearing loss reversible nephrotoxicity and which are both dose-related and levels should be monitored in patients.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 98
Incorrect
-
In relation to ketamine, which of the following statements is TRUE:
Your Answer:
Correct Answer: It is usually associated with tachycardia, increased blood pressure and increased cardiac output.
Explanation:Ketamine has hypnotic, analgesic and local anaesthetic properties. Major adverse effects include Hypertension, Increased cardiac output, Increased ICP, Tachycardia, Tonic-clonic movements, Visual hallucinations and Vivid dreams.
Ketamine is mostly utilized in paediatric anaesthesia, especially when repeated dosing is necessary (such as for serial burns dressings). Ketamine has little effect on respiratory drive, and protective airway reflexes are unaffected. Ketamine is also a bronchial smooth muscle relaxant, hence it plays a unique function in the treatment of severe asthma. -
This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 99
Incorrect
-
You see a 63-year-old man with a history of melaena and epigastric discomfort. For a few months, he's been taking aspirin.
Which of the following statements about aspirin's mechanism of action is correct?Your Answer:
Correct Answer: It inhibits both COX-1 and COX-2 at medium to high doses (500-5000 mg per day)
Explanation:Aspirin inhibits cyclo-oxygenase irreversibly by covalently acetylating the cyclo-oxygenase active site in both COX-1 and COX-2. The production of prostaglandin and thromboxane is reduced as a result. As a result, platelet activation and aggregation are reduced. A single dose of aspirin has a half-life of 7-10 days, which is the time it takes for the bone marrow to produce new platelets.
Aspirin only inhibits COX-1, the enzyme that produces thromboxane A2, at low doses (75 mg per day), and thus has a primarily anti-thrombotic effect.
Aspirin inhibits both COX-1 and COX-2 at medium to high doses (500-5000 mg per day). COX-2 is involved in the production of prostaglandins, so it has an anti-inflammatory effect at these concentrations.
Aspirin, when used as an antipyretic for a viral illness in children, can cause Reye’s syndrome. Reye’s syndrome is a potentially fatal liver disease that causes encephalopathy and liver failure.
The inability of aspirin to reduce platelet production of thromboxane A2, and thus platelet activation and aggregation, is known as aspirin resistance. Although the exact frequency and mechanism of aspirin resistance are unknown, it is thought to affect about 1% of users. Women are more likely than men to experience this phenomenon.
According to new research, taking aspirin on a regular basis lowers the risk of colorectal cancer. It may also protect against cancers of the breast, bladder, prostate, and lungs.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 100
Incorrect
-
A 72-year-old man presents with chest pain that is characteristic of angina. You administer a dose of glyceryl trinitrate (GTN), which rapidly resolved his symptoms. Unfortunately, he also develops an unpleasant side effect.
Which of the following side effects is he most likely to have developed? Select ONE answer only.Your Answer:
Correct Answer: Headache
Explanation:Nitrates are used in the treatment of angina pectoris and the prevention of myocardial ischaemia. Commonly used examples of nitrates are glyceryl trinitrate and isosorbide dinitrate. Unwanted effects, however, are common and can limit therapy, particularly when angina is severe or when patients are unusually sensitive to the effects of nitrates.
The following are common or very common side effects of nitrates
Arrhythmias
Asthenia
Cerebral ischaemia
Dizziness
Drowsiness
Flushing
Headache
Hypotension
Nausea and vomiting
Diarrhoea, syncope and cyanosis can occur, but these are rare side effects. Dry eyes, bradycardia and metabolic acidosis have not been reported. -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 101
Incorrect
-
Compliance is decreased by all but which one of the following:
Your Answer:
Correct Answer: Aging
Explanation:Factors increasing compliance:
Old age
EmphysemaFactors decreasing compliance:
Pulmonary fibrosis
Pulmonary oedema
Atelectasis
Extremes of lung volumes (at higher lung volumes the compliance of the lung becomes less as the lung becomes stiffer) -
This question is part of the following fields:
- Physiology
- Respiratory
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Question 102
Incorrect
-
A 65-year-old man comes for a visit at the clinic with complaints of abdominal pain. On inquiring about drug history, you find out that he has been taking around 8-10 paracetamol to help relieve the pain.
Out of the following, which one is believed to be the main mechanism of action for paracetamol?Your Answer:
Correct Answer: Selective inhibition of COX-3 receptors
Explanation:The FDA categorizes Paracetamol as an NSAID (nonsteroidal anti-inflammatory drug) as it is believed to selectively inhibit cyclo-oxygenase 3 (COX-3) receptors in the brain and spinal cord.
COX-3 is a unique variant of the more known COX-1 and COX-2. It is responsible for the production of prostaglandins in central areas, which sensitizes free nerve endings to the chemical mediators of pain. Therefore, by selectively inhibiting COX-3, paracetamol effectively reduces pain sensation by increasing the pain threshold.
Acetaminophen does not inhibit cyclooxygenase in peripheral tissues and, therefore, has no peripheral anti-inflammatory effects.
The antipyretic actions of acetaminophen are likely attributed to direct action on heat-regulating centres in the brain, resulting in peripheral vasodilation, sweating, and loss of body heat. -
This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 103
Incorrect
-
A 29-year-old man is diagnosed with a severe case of asthma.
In the treatment of acute asthma in adults, which of the following is NOT recommended?Your Answer:
Correct Answer: Nebulised magnesium
Explanation:There is no evidence to support the use of nebulized magnesium sulphate in the treatment of adults at this time.
In adults with acute asthma, the following medication dosages are recommended:
By using an oxygen-driven nebuliser, you can get 5 milligrams of salbutamol.
500 mcg ipratropium bromide in an oxygen-driven nebuliser
Oral prednisolone 40-50 mg
100 mg hydrocortisone intravenous
1.2-2 g magnesium sulphate IV over 20 minutes
When inhaled treatment is ineffective, intravenous salbutamol (250 mcg IV slowly) may be explored (e.g. a patient receiving bag-mask ventilation).Following senior counsel, current ALS recommendations propose that IV aminophylline be explored in severe or life-threatening asthma. If utilized, a loading dose of 5 mg/kg should be administered over 20 minutes, then a 500-700 mcg/kg/hour infusion should be given. To avoid toxicity, serum theophylline levels should be kept below 20 mcg/ml.
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This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 104
Incorrect
-
All of the following cause bronchoconstriction, EXCEPT for:
Your Answer:
Correct Answer: Adrenaline
Explanation:Factors causing bronchoconstriction:
- Via muscarinic receptors
- Parasympathetic stimulation
- Stimulation of irritant receptors
- Inflammatory mediators e.g. histamine, prostaglandins, leukotrienes
- Beta-blockers
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 105
Incorrect
-
A 70-year-old patient presents with a chronic digoxin overdose. She has vomited several times, is extremely tired, and her vision 'appears yellow,' according to her.
Which of the following is a reason for this patient's use of Digifab?Your Answer:
Correct Answer: Coexistent renal failure
Explanation:An antidote for digoxin overdose is digoxin-specific antibody (Digifab). It’s a lyophilized preparation of digoxin-immune ovine Fab immunoglobulin fragments that’s sterile, purified, and lyophilized. These fragments were extracted from the blood of healthy sheep that had been immunised with a digoxin derivative called digoxin-dicarboxymethoxylamine (DDMA), a digoxin analogue that contains the functionally important cyclopentaperhydrophenanthrene:lactone ring moiety coupled to keyhole limpet hemocyanin (KLH).
Digifab has a higher affinity for digoxin than digoxin does for its sodium pump receptor, which is thought to be the site of its therapeutic and toxic effects. When given to a patient who is intoxicated, Digifab binds to digoxin molecules, lowering free digoxin levels and shifting the equilibrium away from binding to receptors, reducing cardio-toxic effects. The kidney and reticuloendothelial system then clear the Fab-digoxin complexes.
The following summarises the indications for Digifab in acute and chronic digoxin toxicity:
Acute digoxin toxicity
Chronic digoxin toxicity
Cardiac arrest
Life-threatening arrhythmia
Potassium level > 5 mmol/l
>10 mg digoxin ingested (adult)
>4 mg digoxin ingested (child)
Digoxin level > 12 ng/ml
Cardiac arrest
Life-threatening arrhythmia
Significant gastrointestinal symptoms
Symptoms of digoxin toxicity -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 106
Incorrect
-
You review a sick patient in resus who has been prescribed mannitol as part of his treatment protocol.
Which SINGLE statement regarding mannitol is true?Your Answer:
Correct Answer: It is irritant to veins and causes phlebitis
Explanation:Mannitol is a low molecular weight compound and is therefore freely filtered at the glomerulus and is not reabsorbed. It, therefore, increases the osmolality of the glomerular filtrate and tubular fluid, increasing urinary volume by an osmotic effect. It also does not cross the blood-brain barrier (BBB).
Mannitol is primarily used to reduce the pressure and volume of cerebrospinal fluid (CSF). It decreases the volume of CSF by:
Decreasing the rate of CSF formation,and;
Withdrawing extracellular fluid from the brain across the BBB
Other uses of mannitol include:
Short-term management of glaucoma
Treatment of rhabdomyolysis
Preserve renal function in peri-operative jaundiced patients
To initiate diuresis in transplanted kidneys
Bowel preparation prior to colorectal procedures
The recommended dose of mannitol for the reduction of CSF pressure/cerebral oedema is 0.25-2g/kg as an intravenous infusion over 30-60 minutes. This can be repeated 1-2 times after 4-8 hours if needed.
Circulatory overload and rebound increases in intracranial pressure may occur following the use of mannitol. It is irritant to tissues and veins and can cause inflammation and phlebitis.
Mannitol causes an expansion of the extracellular fluid space, which may worsen congestive cardiac failure. Contraindications to the use of mannitol include:
Anuria
Intracranial bleeding (except during craniotomy)
Severe cardiac failure
Severe dehydration
Severe pulmonary oedema -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 107
Incorrect
-
A 67-year-old female is admitted under your care with the complaint of shortness of breath and massive pedal oedema. There are fine crepitations up to the mid zones on both lung fields on chest auscultation. When questioned about her medication, she doesn't remember everything she takes but knows that there is a tablet to get rid of excess water.
Out of the following medications, which one increases the osmolality of the filtrate in the glomerulus and the tubule, creating an osmotic effect?Your Answer:
Correct Answer: Mannitol
Explanation:Mannitol is an osmotic diuretic that stops the absorption of water throughout the tubule, thus increasing the osmolality of both glomerular and tubular fluid. It is used to:
1. decrease intraocular pressure in glaucoma
2. decrease intracerebral pressure
3. oliguria.Furosemide is a loop diuretic that inhibits the Na/K/2Cl transported in the ascending limb of the Loop of Henle.
Bendroflumethiazide is a thiazide diuretic which inhibits the Na/Cl transporter.
Spironolactone is a potassium-sparing diuretic that acts as an aldosterone receptor antagonist.
Acetazolamide is a carbonic anhydrase inhibitor.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 108
Incorrect
-
The big toe of a 59-year-old female is red, hot, and swollen. The patient is diagnosed with acute gout. You intend to start her on a nonsteroidal anti-inflammatory medicine (NSAID). Her husband was diagnosed with a peptic ulcer, and she is apprehensive about the potential adverse effects of NSAIDs.
Which of the following NSAIDs has the lowest chance of causing side effects?Your Answer:
Correct Answer: Ibuprofen
Explanation:Non-steroidal anti-inflammatory medications (NSAIDs) have slight differences in anti-inflammatory activity, but there is a lot of diversity in individual response and tolerance to these treatments. Approximately 60% of patients will respond to any NSAID; those who do not respond to one may well respond to another. Pain relief begins soon after the first dose, and a full analgesic effect should be achieved within a week, whereas an anti-inflammatory effect may take up to three weeks to achieve (or to be clinically assessable). If the desired results are not reached within these time frames, another NSAID should be attempted.
By inhibiting the enzyme cyclo-oxygenase, NSAIDs limit the generation of prostaglandins. They differ in their selectivity for inhibiting various types of cyclo-oxygenase; selective inhibition of cyclo-oxygenase-2 is linked to reduced gastrointestinal discomfort. Susceptibility to gastrointestinal effects is influenced by a number of different parameters, and an NSAID should be chosen based on the frequency of side effects.
Ibuprofen is an anti-inflammatory, analgesic, and antipyretic propionic acid derivative. Although it has fewer side effects than other non-selective NSAIDs, its anti-inflammatory properties are less effective. For rheumatoid arthritis, daily doses of 1.6 to 2.4 g are required, and it is contraindicated for illnesses characterized by inflammation, such as acute gout.Because it combines strong efficacy with a low incidence of adverse effects, Naproxen is one of the top choices. It is more likely to cause negative effects than ibuprofen.
Similar to ibuprofen, ketoprofen and diclofenac have anti-inflammatory characteristics, however they have additional negative effects.Indomethacin has a similar or better effect to naproxen, however it comes with a lot of side effects, such as headaches, dizziness, and gastrointestinal problems.
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This question is part of the following fields:
- Musculoskeletal Pharmacology
- Pharmacology
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Question 109
Incorrect
-
Regarding penicillin antibiotics, which of the following statements is CORRECT:
Your Answer:
Correct Answer: Patients with a history of atopy are at higher risk of hypersensitivity reactions.
Explanation:Allergic reactions to penicillins occur in 1 – 10% of exposed individuals; anaphylactic reactions occur in fewer than 0.05% of treated patients. Patients with a history of atopic allergy are at higher risk of anaphylactic reactions to penicillins. Patients with a history of anaphylaxis, urticaria, or rash immediately after penicillin use should not receive a penicillin or other beta-lactam antibiotics; about 0.5 – 6.5 % of penicillin-sensitive patients will also be allergic to the cephalosporins.
Patients with a history of a more minor rash (i.e. non-confluent, non-pruritic rash restricted to a small area of the body) or delayed reaction (rash occurring more than 72 hours after penicillin administration), may not be truly allergic and may be considered for penicillin or beta-lactam treatment in severe infection (although possibility of allergy should be borne in mind). Other beta-lactam antibiotics (including cephalosporins) can be used in these patients.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 110
Incorrect
-
On which of the following types of receptors does loperamide act?
Your Answer:
Correct Answer: Opioid receptors
Explanation:Loperamide inhibits acetylcholine release from the myenteric plexus acts by action on opioid mu-receptors, and this then reduces bowel motility. The intestinal transit time is increased, thereby facilitating water reabsorption.
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This question is part of the following fields:
- Gastrointestinal
- Pharmacology
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Question 111
Incorrect
-
A 28-year-old woman in her second trimester is diagnosed with a psychiatric illness. She is started on treatment with a drug. The treatment results in her baby being born with poor tone, feeding problems, hypothyroidism, and a goitre
Out of the following, which drug is most likely responsible for the baby's condition?Your Answer:
Correct Answer: Lithium
Explanation:In pregnancy and postpartum, lithium is an effective treatment for relapse prevention in bipolar disorder. However, lithium has also been associated with risks during pregnancy for both the mother and the unborn child. Recent large studies have confirmed the association between first-trimester lithium exposure and an increased risk of congenital malformations.
Lithium levels need to be monitored more frequently throughout pregnancy and the postnatal period.
If given in the 1st-trimester, lithium is associated with a risk of fetal cardiac malformations, such as Ebstein’s anomaly.
If given in the 2nd and 3rd-trimesters, there is a risk of the following:
1. hypotonia
2. lethargy
3. feeding problems
4. hypothyroidism
5. goitre
6. nephrogenic diabetes insipidus in the neonate -
This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 112
Incorrect
-
A 46-year-old male who is suffering from a chest infection. You decide to start giving the patient antibiotics, however he is allergic to penicillin. You consult with one of your co-workers about the best choice of antibiotic to give.
From the following choices, which is considered an example of bacteriostatic antibiotic?
Your Answer:
Correct Answer: Trimethoprim
Explanation:Antibiotics that are bactericidal kill bacteria, while antibiotics that are bacteriostatic limit their growth or reproduction. The antibiotics grouped into these two classes are summarized in the table below:
Bactericidal antibiotics
Bacteriostatic antibioticsVancomycin
Metronidazole
Fluoroquinolone, such as ciprofloxacin
Penicillins, such as benzylpenicillin
Cephalosporin, such as ceftriaxone
Co-trimoxazole
Tetracyclines, such as doxycycline
Macrolides, such as erythromycin
Sulphonamides, such as sulfamethoxazole
Clindamycin
Trimethoprim
Chloramphenicol -
This question is part of the following fields:
- Infections
- Pharmacology
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Question 113
Incorrect
-
A 78-year-old man develops renal impairment and hearing loss after inpatient management for sepsis.
Which of these antibiotics is most likely to have been used?Your Answer:
Correct Answer: Gentamicin
Explanation:Gentamicin, an aminoglycoside antibiotic, acts by binding to the 30S subunit of the bacterial ribosome inhibiting the binding of aminoacyl-tRNA, and thus prevents initiation of protein synthesis.
Two of its most notable side effects are reversible nephrotoxicity(caused by the inhibition of protein synthesis in renal cells, which causes acute tubular necrosis) and hearing loss (caused by damage to the vestibular apparatus of the inner ear).
Both side effects are dose-related and occur commonly in the elderly.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 114
Incorrect
-
A 25-year-old patient requires procedural sedation for reduction of an open fracture of his tibia and fibula. You plan on using ketamine as the sedative agent.
Ketamine works as a result of action on what type of receptor? Select ONE answer only.Your Answer:
Correct Answer: N-methyl-D-aspartate (NMDA)
Explanation:Ketamine is the only anaesthetic agent available that has analgesic, hypnotic, and amnesic properties. When used correctly it is a very useful and versatile drug.
Ketamine acts by non-competitive antagonism of the NMDA receptor Ca2+ channel pore and also inhibits NMDA receptor activity by interaction with the phencyclidine binding site.
Ketamine can be used intravenously and intramuscularly. The intramuscular dose is 10 mg/kg, and when used by this route, it acts within 2-8 minutes and has a duration of action of 10-20 minutes. The intravenous dose is 1.5-2 mg/kg administered over a period of 60 seconds. When used intravenously, it acts within 30 seconds and has a duration of action of 5-10 minutes. Ketamine is also effective when administered orally, rectally, and nasally.
Ketamine causes tachycardia, an increase in blood pressure, central venous pressure, and cardiac output, secondary to an increase in sympathetic tone. Baroreceptor function is well maintained, and arrhythmias are uncommon.
The main disadvantage to the use of ketamine is the high incidence of hallucinations, nightmares, and other transient psychotic effects. These can be reduced by the co-administration of a benzodiazepine, such as diazepam or midazolam.
The main side effects of ketamine are:
Nausea and vomiting
Hypertension
Nystagmus
Diplopia
Rash -
This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 115
Incorrect
-
A 4-year-old child has been convulsing for 20 minutes. She has received two doses of lorazepam. She takes phenytoin for maintenance therapy, and you draw up a phenobarbitone infusion.
What dose of phenobarbitone is advised in the treatment of the convulsing child that reaches that stage of the APLS algorithm? Select ONE answer only.Your Answer:
Correct Answer: 20 mg/kg over 30-60 minutes
Explanation:If a convulsing child reaches step 3 of the APLS algorithm, then a phenytoin infusion should be set up at 20 mg/kg over 20 minutes. If they are already taken phenytoin as maintenance therapy, then a phenobarbitone infusion should be set up at 20 mg/kg over 30-60 minutes.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 116
Incorrect
-
When treating diabetic ketoacidosis (DKA), glucose should be given together with insulin as soon as the blood glucose concentration falls below 14 mmol/L in the form of:
Your Answer:
Correct Answer: 10% glucose intravenous infusion at a rate of 125 mL/hour
Explanation:In addition to the sodium chloride 0.9 percent infusion, glucose 10% should be given intravenously (into a large vein with a large-gauge needle) at a rate of 125 mL/hour once blood glucose concentration falls below 14 mmol/litre.
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This question is part of the following fields:
- Endocrine
- Pharmacology
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Question 117
Incorrect
-
Approximately how long is the duration of a lidocaine block (when given with adrenaline):
Your Answer:
Correct Answer: 90 minutes
Explanation:Lidocaine is a tertiary amine that is primarily used as a local anaesthetic but can also be used intravenously in the treatment of ventricular dysrhythmias.
Lidocaine works as a local anaesthetic by diffusing in its uncharged base form through neural sheaths and the axonal membrane to the internal surface of the cell membrane sodium channels. Here it alters signal conduction by blocking the fast voltage-gated sodium channels. With sufficient blockage, the membrane of the postsynaptic neuron will not depolarise and will be unable to transmit an action potential, thereby preventing the transmission of pain signals.
Each 1 ml of plain 1% lidocaine solution contains 10 mg of lidocaine hydrochloride. The maximum safe dose of plain lidocaine is 3 mg/kg. When administered with adrenaline 1:200,000, the maximum safe dose is 7 mg/kg. Because of the risk of vasoconstriction and tissue necrosis, lidocaine should not be used in combination with adrenaline in extremities such as fingers, toes, and the nose.
The half-life of lidocaine is 1.5-2 hours. Its onset of action is rapid within a few minutes, and it has a duration of action of 30-60 minutes when used alone. Its duration of action is prolonged by co-administration with adrenaline (about 90 minutes).
Lidocaine tends to cause vasodilatation when used locally. This is believed to be due mainly to the inhibition of action potentials via sodium channel blocking in vasoconstrictor sympathetic nerves. -
This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 118
Incorrect
-
In the Emergency Department, a 35-year-old woman actively seizing is brought in. She is quickly shifted into the resuscitation room and is administered a dose of benzodiazepine. The seizure is quickly terminated.
Once the patient is stable, she tells you she is a known case of epilepsy and takes phenytoin to control it.
Which of the following is the primary mechanism of action of phenytoin?Your Answer:
Correct Answer: Sodium channel blocker
Explanation:Phenytoin is in the anticonvulsants class of drugs and is used in the management and treatment of the following:
1. epilepsy
2. generalized tonic-clonic seizures
3. complex partial seizures
4. status epilepticus.It works by inactivating the voltage-gated sodium channels responsible for increasing the action potential. It is non-specific and targets almost all voltage-gated sodium channel subtypes. More specifically, phenytoin prevents seizures by inhibiting the positive feedback loop that results in neuronal propagation of high-frequency action potentials.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 119
Incorrect
-
You examine an elderly man who is experiencing chest pain. He doesn't recall all of his medications, but he does know that he takes a diuretic.
The enzyme carbonic anhydrase is inhibited by which of the following diuretics?Your Answer:
Correct Answer: Acetazolamide
Explanation:Acetazolamide is a non-competitive, reversible inhibitor of carbonic anhydrase found in the cytosol of cells and on the brush border of the proximal convoluted tubule. Bicarbonate and hydrogen ions are converted to carbonic acid by carbonic anhydrase, which then converts carbonic acid to carbon dioxide and water. As a result, acetazolamide reduces the availability of hydrogen ions, causing sodium and bicarbonate ions to accumulate in the renal tubule, resulting in diuresis.
The mechanism of action of the various types of diuretics is summarised below:1) Loop diuretics, e.g. furosemide, bumetanide
Act on the Na.K.2Cl co-transporters in the ascending loop of Henlé to inhibit sodium, chloride and potassium reabsorption.2) Thiazide diuretics, e.g. Bendroflumethiazide, hydrochlorothiazide
Act on the Na.Cl co-transporter in the distal convoluted tubule to inhibit sodium and chloride reabsorption.3) Osmotic diuretics, e.g. mannitol
Increases the osmolality of the glomerular filtrate and tubular fluid, increasing urinary volume by an osmotic effect.4) Aldosterone antagonists, e.g. spironolactone
Acts in the distal convoluted tubule as a competitive aldosterone antagonist resulting in inhibition of sodium reabsorption and increasing potassium reabsorption.5) Carbonic anhydrase inhibitors, e.g. acetazolamide
Inhibit the enzyme carbonic anhydrase preventing the conversion of bicarbonate and hydrogen ions into carbonic acid. -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 120
Incorrect
-
Regarding oral rehydration therapy, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: Oral rehydration solutions should be slightly hyperosmolar.
Explanation:Oral rehydration therapy (ORT) is a fluid replacement strategy used to prevent or treat dehydration. It is less invasive than other strategies for fluid replacement and has successfully lowered the mortality rate of diarrhoea in developing countries. Oral rehydration solutions should be slightly hypo-osmolar (about 250 mmol/litre) to prevent the possible induction of osmotic diarrhoea.
ORT contains glucose (e.g. 90 mmol/L in dioralyte). The addition of glucose improves sodium and water absorption in the bowel and prevents hypoglycaemia. It also contains essential mineral salts.
Current NICE guidance recommends that 50 ml/kg is given over 4 hours for the treatment of mild dehydration.
Once rehydrated, a child should continue with their usual daily fluid intake plus 200 ml ORT after each loose stool. In an infant, give ORT at 1-1.5 x the normal feed volume and in an adult, give 200-400 ml after each loose stool. -
This question is part of the following fields:
- Fluids And Electrolytes
- Pharmacology
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Question 121
Incorrect
-
A patient with pronounced tremor, muscle contractions, muscle spasms, and slowness of movement is brought in by his family. He has a long history of mental health issues for which he is currently treated with a variety of medications.
Which of the medications listed below is most likely to be the cause of these side effects?Your Answer:
Correct Answer: Haloperidol
Explanation:Acute dyskinesias and dystonic reactions, tardive dyskinesia (rhythmic, involuntary movements of the tongue, face, and jaw), Parkinsonism (tremor, bradykinesia, and rigidity), akinesia, akathisia, and neuroleptic malignant syndrome are all examples of extrapyramidal side effects. They are caused by dopamine depletion or blockade in the basal ganglia; this lack of dopamine frequently mimics idiopathic extrapyramidal pathologies.
The first-generation antipsychotics, which are strong dopamine D2 receptor antagonists, are the drugs most commonly associated with extrapyramidal side effects. Haloperidol and fluphenazine are the two drugs in this class that are most commonly associated with extrapyramidal side effects. Extrapyramidal adverse effects are less common in second-generation antipsychotics (e.g., olanzapine) than in first-generation antipsychotics.
Other drugs are linked to extrapyramidal symptoms as well, but at a lower rate. Some antidepressants, lithium, various anticonvulsants, antiemetics, and, in rare cases, oral contraceptive agents are among them.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 122
Incorrect
-
You're a member of the cardiac arrest team, and you're helping to resuscitate an elderly gentleman who had collapsed at home. The team leader requests that you administer an adrenaline shot.
Which of the following statements about adrenaline is FALSE?Your Answer:
Correct Answer: The IM dose in anaphylaxis is 1 ml of 1:1000
Explanation:Adrenaline (epinephrine) is a sympathomimetic amine that binds to alpha- and beta-adrenergic receptors and acts as an agonist. It is active at both alpha and beta receptors in roughly equal amounts.
When taken orally, it becomes inactive. Subcutaneous absorption is slower than intramuscular absorption. In cardiac arrest, it is well absorbed from the tracheal mucosa and can be given through an endotracheal tube.
At the adrenergic synapse, catechol-O-methyltransferase (COMT) and monoamine oxidase (MAO) metabolise it primarily. The inactive products are then passed through the kidneys and excreted in the urine.
In adult cardiac arrest, the IV dose is 1 mg, which is equal to 10 ml of 1:10000 or 1 ml of 1:1000. In anaphylaxis, the IM dose is 0.5 ml of 1:1000. (500 mcg).
In open-angle glaucoma, adrenaline causes mydriasis and lowers pressure.
Adrenaline is used in cardiopulmonary resuscitation, the treatment of severe croup, and the emergency management of acute allergic and anaphylactic reactions (as a nebuliser solution).
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 123
Incorrect
-
A 65-year-old man presents with a red, hot, swollen great toe. A diagnosis of acute gout is made. His past medical history includes heart failure and type 2 diabetes mellitus.
Which of the following is the most appropriate medication to use in the treatment of his gout? Select ONE answer only.Your Answer:
Correct Answer: Colchicine
Explanation:In the absence of any contra-indications, high-dose NSAIDs are the first-line treatment for acute gout. Naproxen 750 mg as a stat dose followed by 250 mg TDS is a commonly used and effective regime.
Aspirin should not be used in gout as it reduces the urinary clearance of urate and interferes with the action of uricosuric agents. Naproxen, Diclofenac or Indomethacin are more appropriate choices.
Allopurinol is used prophylactically, preventing future attacks by reducing serum uric acid levels. It should not be started in the acute phase as it increases the severity and duration of symptoms.
Colchicine acts on the neutrophils, binding to tubulin to prevent neutrophil migration into the joint. It is as effective as NSAIDs in relieving acute attacks. It also has a role in prophylactic treatment if Allopurinol is not tolerated.
NSAIDs are contra-indicated in heart failure as they can cause fluid retention and congestive cardiac failure. Colchicine is the preferred treatment in patients with heart failure or those who are intolerant of NSAIDs. -
This question is part of the following fields:
- Musculoskeletal Pharmacology
- Pharmacology
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Question 124
Incorrect
-
Which of the following is NOT a contraindication to the use of diazepam:
Your Answer:
Correct Answer: Acute alcohol withdrawal
Explanation:Benzodiazepines are used to treat symptoms in patients with acute alcohol withdrawal syndrome.
Benzodiazepines are contraindicated in:
Respiratory depression
Marked neuromuscular respiratory weakness, such as unstable myasthenia gravis
Obstructive sleep apnoea syndrome (symptoms may be aggravated)
Severe hepatic impairment (the elimination half-life of diazepam may be prolonged; increased risk of coma)
Phobic or obsessional states, chronic psychosis or hyperkinesis (paradoxical reactions may occur). -
This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 125
Incorrect
-
Compliance is greater in all but which one of the following:
Your Answer:
Correct Answer: Pulmonary oedema
Explanation:Compliance changes at different lung volumes. Initially at lower lung volumes the compliance of the lung is poor and greater pressure change is required to cause a change in volume. This occurs if the lungs become collapsed for a period of time. At functional residual capacity (FRC) compliance is optimal since the elastic recoil of the lung tending towards collapse is balanced by the tendency of the chest wall to spring outwards. At higher lung volumes the compliance of the lung again becomes less as the lung becomes stiffer. At all volumes, the base of the lung has a greater compliance than the apex. Patients with emphysema have increased compliance. Compliance is affected by a person’s age, sex and height.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 126
Incorrect
-
Glucagon may be used as an antidote for overdose with which of the following:
Your Answer:
Correct Answer: Beta blockers
Explanation:Glucagon is a peptide hormone that is produced and secreted by alpha cells of the islets of Langerhans, which are located in the endocrine portion of the pancreas. The main physiological role of glucagon is to stimulate hepatic glucose output, thereby leading to increases in glycaemia. It provides the major counter-regulatory mechanism to insulin in maintaining glucose homeostasis.
Hypoglycaemia is the principal stimulus for the secretion of glucagon but may also be used as an antidote in beta-blocker overdose and in anaphylaxis in patients on beta-blockers that fail to respond to adrenaline.
Glucagon then causes:
Glycogenolysis
Gluconeogenesis
Lipolysis in adipose tissue
The secretion of glucagon is also stimulated by:
Adrenaline
Cholecystokinin
Arginine
Alanine
Acetylcholine
The secretion of glucagon is inhibited by:
Insulin
Somatostatin
Increased free fatty acids
Increased urea productionGlycolysis is the metabolic pathway that converts glucose into pyruvate. The free energy released by this process is used to form ATP and NADH. Glycolysis is inhibited by glucagon, and glycolysis and gluconeogenesis are reciprocally regulated so that when one cell pathway is activated, the other is inactive and vice versa.
Glucagon has a minor effect of enhancing lipolysis in adipose tissue. Lipolysis is the breakdown of lipids and involves the hydrolysis of triglycerides into glycerol and free fatty acids. It makes fatty acids available for oxidation.
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This question is part of the following fields:
- Endocrine
- Pharmacology
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Question 127
Incorrect
-
A 42-year-old woman presents with face swelling prominently affecting her upper lip and hands. She has previously been diagnosed with hereditary angioedema.
Which of these is the most appropriate management option for this acute attack?Your Answer:
Correct Answer: Fresh frozen plasma
Explanation:Hereditary angioedema is inherited as an autosomal dominant disorder and is caused by deficiency of C1 esterase inhibitor, a protein that forms part of the complement system.
Attacks can be precipitated by stress and minor surgical procedures. Clinical features of hereditary angioedema include oedema of the skin and mucous membranes commonly affecting the face, tongue and extremities.
Angioedema and anaphylaxis due to a deficiency of C1 esterase inhibitor are resistant to adrenaline, steroids and antihistamines. Treatment is with fresh frozen plasma or C1 esterase inhibitor concentrate, which contains C1 esterase inhibitor.
Short-term prophylaxis for events that may precipitate angioedema attack is achieved with C1 esterase inhibitor or fresh frozen plasma infusions before the event while long-term prophylaxis can be achieved with antifibrinolytic drugs (tranexamic acid) or androgenic steroids.
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This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 128
Incorrect
-
For which of the following infections is phenoxymethylpenicillin (penicillin V) primarily used?
Your Answer:
Correct Answer: Streptococcal tonsillitis
Explanation:Phenoxymethylpenicillin (penicillin V) is less active than benzylpenicillin but both have similar antibacterial spectrum. Because penicillin V is gastric-acid stable, it is suitable for oral administration, but should not be used for serious infections as absorption can be unpredictable and plasma concentrations can be variable.
Its uses are:
1. mainly for respiratory tract infections in children
2. for streptococcal tonsillitis
3. for continuing treatment after one or more injections of benzylpenicillin when clinical response has begun.
4. for prophylaxis against streptococcal infections following rheumatic fever and against pneumococcal infections following splenectomy or in sickle-cell disease.It should not be used for meningococcal or gonococcal infections.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 129
Incorrect
-
On ambulatory blood pressure monitoring, a 48-year-old Caucasian man has an average BP reading of 152/96 mmHg (ABPM).
Which of the following would be the patient's first-line drug treatment?Your Answer:
Correct Answer: Ramipril
Explanation:An ambulatory blood pressure reading of >150/95 is classified as stage 2 hypertension, according to the NICE care pathway for hypertension, and the patient should be treated with an antihypertensive drug.
A calcium-channel blocker, such as amlodipine, would be the most appropriate medication for a 48-year-old Afro-Caribbean man.
An ACE inhibitor, such as ramipril, or a low-cost angiotensin-II receptor blocker (ARB), such as losartan, would be the most appropriate medication for a 48-year-old Caucasian man.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 130
Incorrect
-
Fusidic acid is primarily indicated for infections caused by which of the following microorganisms:
Your Answer:
Correct Answer: Staphylococcal infections
Explanation:Fusidic acid is a narrow spectrum antibiotic used for staphylococcal infections, primarily topically for minor staphylococcal skin (impetigo) or eye infection. It is sometimes used orally for penicillin-resistant staphylococcal infection, including osteomyelitis or endocarditis, in combination with other antibacterials.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 131
Incorrect
-
Which of the following is NOT a typical feature of benzodiazepine toxicity:
Your Answer:
Correct Answer: Hyperventilation
Explanation:Features of benzodiazepine toxicity include: drowsiness, ataxia, dysarthria, nystagmus, occasionally respiratory depression and coma
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
-
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Question 132
Incorrect
-
You plan to use plain 1% lidocaine for a ring block on a finger that needs suturing.
Which SINGLE statement regarding the use of 1% lidocaine, in this case, is true?Your Answer:
Correct Answer: Lidocaine works by blocking fast voltage-gated sodium channels
Explanation:Lidocaine is a tertiary amine that is primarily used as a local anaesthetic but can also be used intravenously in the treatment of ventricular dysrhythmias.
Lidocaine works as a local anaesthetic by diffusing in its uncharged base form through neural sheaths and the axonal membrane to the internal surface of the cell membrane sodium channels. Here it alters signal conduction by blocking the fast voltage-gated sodium channels. With sufficient blockage, the membrane of the postsynaptic neuron will not depolarise and will be unable to transmit an action potential, thereby preventing the transmission of pain signals.
Each 1 ml of plain 1% lidocaine solution contains 10 mg of lidocaine hydrochloride. The maximum safe dose of plain lidocaine is 3 mg/kg. When administered with adrenaline 1:200,000, the maximum safe dose is 7 mg/kg. Because of the risk of vasoconstriction and tissue necrosis, lidocaine should not be used in combination with adrenaline in extremities such as fingers, toes, and the nose.
The half-life of lidocaine is 1.5-2 hours. Its onset of action is rapid within a few minutes, and it has a duration of action of 30-60 minutes when used alone. Its duration of action is prolonged by co-administration with adrenaline (about 90 minutes).
Lidocaine tends to cause vasodilatation when used locally. This is believed to be due mainly to the inhibition of action potentials via sodium channel blocking in vasoconstrictor sympathetic nerves. -
This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 133
Incorrect
-
Regarding ciprofloxacin, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: Ciprofloxacin decreases plasma concentrations of theophylline.
Explanation:Ciprofloxacin increases plasma concentrations of theophylline. There is an increased risk of convulsions when quinolones are given with NSAIDs or theophylline. There is an increased risk of tendon damage when quinolones are given with corticosteroids. Quinolones are known to increase the QT-interval and should not be taken with concomitantly with other drugs that are known to cause QT-interval prolongation. There is an increased risk of myopathy when erythromycin or clarithromycin are taken with simvastatin or atorvastatin.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 134
Incorrect
-
A 55-year-old female is urgently rushed into the Emergency Department as she complains of chest pain that is worse on breathing, shortness of breath, palpitations, and haemoptysis.
She undergoes a CT pulmonary angiogram, which reveals a large pulmonary embolus. She is immediately started on heparin and shifted to the acute medical ward.
Which of the following statements is true regarding heparin?Your Answer:
Correct Answer: It activates antithrombin III
Explanation:Heparin is a polymer of glycosaminoglycan. It occurs naturally and is found in mast cells. Clinically, it is used in two forms:
1. Unfractionated: widely varying polymer chain lengths
2. Low molecular weight: Smaller polymers onlyHeparin works by binding to and activating the enzyme inhibitor antithrombin III. Antithrombin III inactivates thrombin (factor IIa) by forming a 1:1 complex with thrombin. The heparin-antithrombin III complex also inhibits factor Xa and some other proteases involved with clotting. The heparin-ATIII complex can also inactivate IX, XI, XII, and plasmin.
Heparin is not thrombolytic or fibrinolytic. It prevents the progression of existing clots by inhibiting further clotting. The lysis of existing clots relies on endogenous thrombolytics.
Heparin is used for:
1. Prevention and treatment of venous thromboembolism
2. Treatment of disseminated intravascular coagulation
3. Treatment of fat embolism
4. Priming of haemodialysis and cardiopulmonary bypass machinesThere is no evidence that heparin is superior to low-molecular-weight heparins in preventing mortality from thrombosis.
Vitamin K is used to reverse the effects of warfarin but not heparin. For heparin, protamine sulphate is used to counteract its effects.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 135
Incorrect
-
A 62-year-old man complains of chest pain and goes to the emergency room. You diagnose him with an acute coronary syndrome and prescribe enoxaparin as part of his treatment plan.
Enoxaparin inactivates which of the following?Your Answer:
Correct Answer: Thrombin
Explanation:Enoxaparin is a low molecular weight heparin (LMWH) that works in the same way as heparin by binding to and activating the enzyme inhibitor antithrombin III. Antithrombin III inactivates thrombin by forming a 1:1 complex with it. Factor Xa and a few other clotting proteases are also inhibited by the heparin-antithrombin III complex.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 136
Incorrect
-
You are attending to a patient that has presented with a severe headache in the Emergency Department. The patient has signs of cerebral oedema and raised intracranial pressure.
You discuss the case with the on-call neurology registrar and decide to prescribe Mannitol. The nurse assisting you asks you to reconsider this management plan as she suspects the patient has a contraindication to Mannitol.
Out of the following, what is a contraindication to mannitol?Your Answer:
Correct Answer: Severe cardiac failure
Explanation:Mannitol is the most widely used osmotic diuretic that is most commonly used to reduce cerebral oedema and intracranial pressure.
It is recommended to use mannitol for the reduction of CSF pressure/cerebral oedema in a dose of 0.25-2 g/kg as an intravenous infusion over 30-60 minutes. This can be repeated 1-2 times after 4-8 hours if needed.Mannitol has several contraindications and some of them are listed below:
1. Anuria due to renal disease
2. Acute intracranial bleeding (except during craniotomy)
3. Severe cardiac failure
4. Severe dehydration
5. Severe pulmonary oedema or congestion
6. Known hypersensitivity to mannitol -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 137
Incorrect
-
After collapsing at home, a 75-year-old man is transported in an ambulance. He is now awake, but he is experiencing palpitations and chest pain. He is transported to resuscitation and placed on a cardiac monitor, which indicates that he is in VT. An amiodarone infusion is set up.
Which of the following statements about amiodarone side effects is correct?Your Answer:
Correct Answer: It can cause jaundice
Explanation:Amiodarone has a lot of potential toxic side effects, so it’s important to get a full clinical evaluation before starting treatment with it.
The following are some of the most common amiodarone side effects:
Arrhythmias
Corneal microdeposits
Hepatic disorders
Hyperthyroidism
Hypothyroidism
Hepatic disorders and jaundice
Nausea
Peripheral neuropathy
Respiratory disorders (including lung fibrosis)
Sleep disturbance
Skin reactions
QT prolongationAmiodarone can cause optic neuritis, which is a very rare side effect. If this happens, the amiodarone should be stopped right away because it poses a risk of blindness.
Most people who take amiodarone develop corneal microdeposits, which go away once the medication is stopped and rarely cause vision problems.
Amiodarone has a chemical structure that is similar to that of thyroxine and can bind to the nuclear thyroid receptor. It can cause both hypothyroidism and hyperthyroidism, though hypothyroidism is far more common, with 5-10% of patients suffering from it.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 138
Incorrect
-
Question 139
Incorrect
-
Which of the following is a contraindication to using nitrous oxide:
Your Answer:
Correct Answer: Raised intracranial pressure
Explanation:Nitrous oxide should not be utilized in patients with an air-containing confined area because it diffuses into these spaces, causing a rise in pressure. This includes circumstances like pneumothorax, intracranial air after a head injury, imprisoned air from a recent undersea dive, a recent intraocular gas injection, or intestinal blockage. Nitrous oxide increases cerebral blood flow and should be avoided in individuals who have or are at risk of having high intracranial pressure.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 140
Incorrect
-
A patient presents with severe vomiting. They take a maintenance dose of 12.5 mg of prednisolone daily for their COPD. They are unable to swallow or keep down tablets at present, and you plan on converting them to IV hydrocortisone.
What dose of hydrocortisone is equivalent to this dose of prednisolone? Select ONE answer only.Your Answer:
Correct Answer: 50 mg
Explanation:Prednisolone is four times more potent than hydrocortisone, and therefore, a dose of 12.5 mg would be equivalent to 50 mg of hydrocortisone.
The following table summarises the relative potency of the main corticosteroids compared with hydrocortisone:
Corticosteroid
Potency relative to hydrocortisone
Prednisolone
4 times more potent
Triamcinolone
5 times more potent
Methylprednisolone
5 times more potent
Dexamethasone
25 times more potent -
This question is part of the following fields:
- Endocrine Pharmacology
- Pharmacology
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Question 141
Incorrect
-
A 54-year-old man with a long history of poorly controlled hypertension complains of a headache and vision blurring today. In triage, his blood pressure is 210/192 mmHg. A CT head scan is scheduled to rule out the possibility of an intracranial haemorrhage. You make the diagnosis of hypertensive encephalopathy and rush the patient to reus to begin blood pressure-lowering treatment. He has a history of brittle asthma, for which he has been admitted to the hospital twice in the last year.
Which of the following is the patient's preferred drug treatment?Your Answer:
Correct Answer: 25% of the mean arterial pressure over the first hour
Explanation:End-organ damage (e.g. encephalopathy, intracranial haemorrhage, acute myocardial infarction or ischaemia, dissection, pulmonary oedema, nephropathy, eclampsia, papilledema, and/or angiopathic haemolytic anaemia) characterises a hypertensive emergency (also known as ‘accelerated hypertension’ or malignant hypertension’ It’s a life-threatening condition that necessitates rapid blood pressure reduction to avoid end-organ damage and a negative outcome.
Hypertensive encephalopathy is a syndrome that includes headaches, seizures, visual changes, and other neurologic symptoms in people who have high blood pressure. It is reversible if treated quickly, but it can progress to coma and death if not treated properly.
Any patient with suspected hypertensive encephalopathy should have an urgent CT scan to rule out an intracranial haemorrhage, as rapid blood pressure reduction could be dangerous in these circumstances.
The drug of choice is labetalol, which reduces blood pressure steadily and consistently without compromising cerebral blood flow.
An initial reduction of approximately 25% in mean arterial pressure (MAP) over an hour should be aimed for, followed by a further controlled MAP reduction over the next 24 hours. In patients who are unable to take beta-blockers, nicardipine can be used as a substitute. -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 142
Incorrect
-
A 39-year-old man who is suffering from a bacterial infection require antibiotic treatment. You need to figure out which antibiotic is most suitable. Listed below are antimicrobial drugs.
Which one is a nucleic acid synthesis inhibitor?
Your Answer:
Correct Answer: Ciprofloxacin
Explanation:Ciprofloxacin and other quinolone antibiotics work by blocking DNA gyrase, an enzyme that compresses bacterial DNA into supercoils, as well as a type II topoisomerase, which is required for bacterial DNA separation. As a result, they prevent nucleic acid synthesis.
The following is a summary of the many modes of action of various types of antimicrobial agents:Action Mechanisms- Examples:
Cell wall production is inhibited
Vancomycin
Vancomycin
CephalosporinsThe function of the cell membrane is disrupted
Nystatin
Polymyxins
Amphotericin BInhibition of protein synthesis
Chloramphenicol
Macrolides
Aminoglycosides
TetracyclinesNucleic acid synthesis inhibition
Quinolones
Trimethoprim
Rifampicin
5-nitroimidazoles
Sulphonamides
Anti-metabolic activity
Isoniazid -
This question is part of the following fields:
- Infections
- Pharmacology
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Question 143
Incorrect
-
Aldin is a 24-year-old male patient who arrives at the emergency department diagnosed with psittacosis based on his symptoms and history of being a pigeon enthusiast. Which of the following is the causative bacteria of psittacosis?
Your Answer:
Correct Answer: Chlamydia psittaci
Explanation:Chlamydia psittaci is a microorganism that is commonly found in birds.
These bacteria can infect people and cause psittacosis. Psittacosis is an infectious disease that may cause high fever and pneumonia associated with headaches, altered mental state, and hepatosplenomegaly.
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This question is part of the following fields:
- Infections
- Microbiology
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Question 144
Incorrect
-
A young male has presented to you with respiratory depression and small pupils on examination. You diagnose opioid overdose and immediately start therapy with Naloxone.
Which of the following statements is TRUE regarding naloxone?Your Answer:
Correct Answer: It can be given by a continuous infusion if repeated doses are required
Explanation:Naloxone is a short-acting, specific antagonist of mu(μ)-opioid receptors. It is used to reverse the effects of opioid toxicity.
It can be given by a continuous infusion if repeated doses are required and the infusion rate is adjusted according to the vital signs. Initially, the infusion rate can be set at 60% of the initial resuscitative IV dose per hour.
Naloxone has a shorter duration of action (6-24 hours) than most opioids and so close monitoring according to the respiratory rate and depth of coma and repeated injections are necessary. When repeated doses are needed in opioid addicts, naloxone administration may precipitate a withdrawal syndrome with abdominal cramps, nausea and diarrhoea, but these usually settle within 2 hours.
An initial dose of 0.4 to 2 mg can be given intravenously and can be repeated at 2 to 3-minute intervals to a maximum of 10mg.
If the intravenous route is inaccessible, naloxone can be administered via an IO line, subcutaneously (SQ), IM, or via the intranasal (IN) route.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 145
Incorrect
-
You intend to suture a hand wound with plain 1 percent lidocaine.
In 1 mL of plain 1 percent lidocaine solution, how much lidocaine hydrochloride is there?Your Answer:
Correct Answer: 10 mg lidocaine hydrochloride
Explanation:10 mg of lidocaine hydrochloride is contained in each 1 mL of plain 1 percent lidocaine solution.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
-
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Question 146
Incorrect
-
After collapsing in his nursing home, a 70-year-old man is brought into the ER. He is a known case of diabetes mellitus and is on medication for it. An RBS of 2.5 mmol/L (3.9-5.5 mmol/L) is recorded in the ER.
Out of the following, which medication for diabetes mellitus is MOST likely responsible for his hypoglycaemic episode?Your Answer:
Correct Answer: Pioglitazone
Explanation:Pioglitazone is used to treat type 2 diabetes mellitus. It selectively stimulates the nuclear receptor peroxisome proliferator-activated receptor gamma (PPAR-γ) and to a lesser extent PPAR-α.
Of the medications mentioned in this question, only pioglitazone is a recognized cause of hypoglycaemia.
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This question is part of the following fields:
- Endocrine Pharmacology
- Pharmacology
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Question 147
Incorrect
-
An 85-year-old woman is brought in from her nursing home. She arrives in the Emergency Department and appears confused. The staff member from the nursing home accompanying her informs you that she takes a water tablet.
From her past medical history and records, you deduce that the water tablet is a loop diuretic.
Which of the following parts of a nephron does a loop diuretic act on?Your Answer:
Correct Answer: Ascending loop of Henlé
Explanation:Loop diuretics are drugs used to manage and treat fluid overload associated with CHF, liver cirrhosis, and renal disease. The drugs commonly used are:
Furosemide
Bumetanide
Torsemide
Ethacrynic AcidLoop diuretics act on the apical membrane of the thick ascending loop of Henle and inhibit the Na-K-Cl cotransporter. This blocks the reabsorption of sodium and chloride and results in salt-water excretion. This relieves congestion and reduces oedema.
Other diuretics act on the following part of the nephron:
1. Thiazide diuretics – Na/Cl co-transporter in the distal convoluted tubule
2. Osmotic diuretics – PCT and the loop of Henle
3. Aldosterone antagonists – distal convoluted tubule
4. Carbonic anhydrase inhibitors – inhibit the carbonic anhydrase and act on proximal tubular cells -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 148
Incorrect
-
Regarding drug interactions with erythromycin, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: Erythromycin decreases plasma levels of warfarin.
Explanation:Erythromycin and clarithromycin inhibit cytochrome P450-mediated metabolism of warfarin, phenytoin and carbamazepine and may lead to accumulation of these drugs. There is an increased risk of myopathy (due to cytochrome P450 enzyme CYP3A4 inhibition) if erythromycin or clarithromycin is taken with atorvastatin or simvastatin. Erythromycin increases plasma concentrations of theophylline, and theophylline may also reduce absorption of oral erythromycin. All macrolides can prolong the QT-interval and concomitant use of drugs that prolong the QT interval is not recommended.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 149
Incorrect
-
Which of the following statements is incorrect regarding potassium replacement?
Your Answer:
Correct Answer: Oral potassium supplements are often required for patients taking spironolactone.
Explanation:It is very seldom that potassium supplements are required with the small doses of diuretics given to treat hypertension. Potassium-sparing diuretics like spironolactone (rather than potassium supplements), are recommended for hypokalaemia prevention when diuretics are given to eliminate oedema, such as furosemide or the thiazides.
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This question is part of the following fields:
- Fluids And Electrolytes
- Pharmacology
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Question 150
Incorrect
-
A 59-year-old man presents to the emergency room with chest pain. He was recently released from the hospital after receiving abciximab during coronary angioplasty.
Which of the following is abciximab (ReoPro) mechanism of action?Your Answer:
Correct Answer: Antagonism of the glycoprotein IIb/IIIa receptor
Explanation:Abciximab (ReoPro) is a glycoprotein IIb/IIIa receptor antagonist that is a chimeric monoclonal antibody. It is primarily used during and after coronary artery procedures such as angioplasty to inhibit platelet aggregation.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 151
Incorrect
-
A 30-year-old patient has a mild exacerbation of his asthma. His steroid inhaler ran out a couple of weeks ago, and he has not replaced it.
Which of these statements describes the mechanism of action of corticosteroids in asthma?
Your Answer:
Correct Answer: Reduction of bronchial inflammation
Explanation:Inhaled corticosteroids suppresses airway inflammation seen in asthma by downregulating pro-inflammatory proteins.
They also appear to reverse components of asthma-induced structural changes (airway remodelling), including increased vascularity of the bronchial wall.
Corticosteroids reduces the number of inflammatory cells (eosinophils, T lymphocytes, mast cells, and dendritic cells) in the airways. -
This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 152
Incorrect
-
Despite taking the oral contraceptive pill, a 29-year-old woman becomes pregnant. During a medication review, you discover that she is epileptic and that her antiepileptic therapy has recently been changed.
Which of the following antiepileptics is most likely to impair the oral contraceptive pill's effectiveness?Your Answer:
Correct Answer: Carbamazepine
Explanation:The metabolism of ethinyl oestradiol and progestogens has been shown to be increased by enzyme-inducing antiepileptics. The oral contraceptive pill (OCP) is less effective in preventing pregnancy as a result of this increased breakdown.
Antiepileptic drugs that induce enzymes include:
Carbamazepine
Phenytoin
Phenobarbital
TopiramateAntiepileptics that do not induce enzymes are unlikely to affect contraception. Non-enzyme-inducing anticonvulsants include the following:
Clonazepam
Gabapentin
Levetiracetam
Piracetam
Sodium valproate is a type of valproate that is used toLamotrigine is an antiepileptic drug that does not cause the production of enzymes. It does, however, require special consideration, unlike other non-enzyme-inducing antiepileptics. The OCP does not appear to affect epilepsy directly, but it does appear to lower lamotrigine levels in the blood. This could result in a loss of seizure control and the occurrence of seizures.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 153
Incorrect
-
A 32-year-old man is dehydrated as he presents with severe vomiting and diarrhoea. He urgently requires resuscitation with intravenous fluid administration. He is also administered metoclopramide.
Which of the following is the true mechanism of action of metoclopramide?Your Answer:
Correct Answer: Dopamine receptor antagonism
Explanation:Metoclopramide is used to treat nausea and vomiting. It works by blocking the central and peripheral D2 (dopamine 2) receptors in the medullary chemoreceptor trigger zone in the vomiting centre (area postrema). It decreases the sensitivity of the visceral sensory nerves that transmit from the GI system to the vomiting centre. Blockade of inhibitory dopamine receptors in the GI tract may allow stimulatory actions of ACh at muscarinic synapses to predominate.
At high doses, metoclopramide also blocks type-2 serotonin receptors though the effect is much weaker.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 154
Incorrect
-
You examine a 79-year-old woman who has had hypertension and atrial fibrillation in the past. Her most recent blood tests show that she has severe renal impairment.
Which medication adjustments should you make in this patient's case?Your Answer:
Correct Answer: Reduce dose of digoxin
Explanation:Digoxin is excreted through the kidneys, and impaired renal function can lead to elevated digoxin levels and toxicity.
The patient’s digoxin dose should be reduced in this case, and their digoxin level and electrolytes should be closely monitored. -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 155
Incorrect
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You examine a 50-year-old female who has a swollen, painful right big toe. She has a history of gout, and this discomfort is identical to prior relapses, according to her. She is currently taking 200 mg of allopurinol per day and has been for the last year. This is her second round of acute gout within this time period. She has no prior medical history to speak of and does not take any other medications. She doesn't have any known drug allergies.
Which of the following management options is the SINGLE MOST APPROPRIATE?Your Answer:
Correct Answer: Continue with the allopurinol and commence naproxen
Explanation:Allopurinol should not be started during an acute gout episode because it can both prolong and trigger another acute attack. Allopurinol should be continued in patients who are currently taking it, and acute attacks should be treated as usual with NSAIDs or colchicine, as needed.
Non-steroidal anti-inflammatory medications (NSAIDs), such as naproxen, are the first-line treatment for acute gout attacks. Colchicine can be used in situations where NSAIDs are contraindicated, such as in patients with hypertension or those who have had a history of peptic ulcer disease. Because there is no reason for this patient to avoid NSAIDs, naproxen would be the medicine of choice from the list above.
It would be reasonable to titrate up the allopurinol dose once the acute episode has subsided, targeting <6 mg/dl (<360 µmol/l) plasma urate levels .
Febuxostat (Uloric) is a drug that can be used instead of allopurinol to treat persistent gout. -
This question is part of the following fields:
- Musculoskeletal Pharmacology
- Pharmacology
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Question 156
Incorrect
-
You review a 46-year-old woman who has recently been prescribed antibiotics for a urinary tract infection. She suffers from COPD and is currently prescribed salbutamol and Seretide inhalers, and Phyllocontin continus. Since starting the antibiotics, she has been experiencing nausea, vomiting and abdominal pain.
Which of the following antibiotics is she MOST LIKELY to have been prescribed for her UTI? Select ONE answer only .Your Answer:
Correct Answer: Ciprofloxacin
Explanation:Phyllocontin continus contains aminophylline (a mixture of theophylline and ethylenediamine), a bronchodilator used in the management of COPD and asthma.
This patient is exhibiting symptoms of theophylline toxicity, which may have been triggered by the prescription of the antibiotic. Quinolone antibiotics, such as ciprofloxacin and levofloxacin, and macrolide antibiotics, such as erythromycin, increase the plasma concentration of theophyllines and can lead to toxicity.
The drugs that commonly affect the half-life and the plasma concentration of theophylline are summarised in the table below:
Drugs increasing plasma concentration of theophylline
Drugs decreasing plasma concentration of theophylline
Calcium channel blockers, e.g. Verapamil
Cimetidine
Fluconazole
Macrolides, e.g. erythromycin
Quinolones, e.g. ciprofloxacin
Methotrexate
Barbiturates
Carbamazepine
Phenobarbitol
Phenytoin (and fosphenytoin)
Rifampicin
St. John’s wort -
This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 157
Incorrect
-
In a ward round, you come across a patient's treatment chart prescribed an antibiotic to fight his infection. This antibiotic is a protein synthesis inhibitor.
Which of the following antimicrobial drugs is prescribed to this patient?Your Answer:
Correct Answer: Gentamicin
Explanation:Gentamicin, an aminoglycoside antibiotic, acts by binding to the 30S subunit of the bacterial ribosome inhibiting the binding of aminoacyl-tRNA and thus preventing initiation of protein synthesis.
Vancomycin inhibits cell wall peptidoglycan formation by binding the D-Ala-D-Ala portion of cell wall precursors.
Penicillins and cephalosporins are the major antibiotics that inhibit bacterial cell wall synthesis. They inactivate transpeptidases that help cross-link peptidoglycans in cell walls.
Metronidazole and the other 5-nitroimidazole agents inhibit nucleic acid synthesis by forming toxic free radical metabolites in the bacterial cell that damage DNA.
Ciprofloxacin inhibits prokaryotic enzymes topoisomerase II (DNA gyrase) and topoisomerase IV.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 158
Incorrect
-
Regarding airway resistance, which of the following statements is CORRECT:
Your Answer:
Correct Answer: Airway resistance is predominantly determined by the radius of the airway as described by Poiseuille's law.
Explanation:Flow through airways is described by Darcy’s law which states that flow is directly proportional to the mouth-alveolar pressure gradient and inversely proportional to airway resistance. Airway resistance is primarily determined by the airway radius according to Poiseuille’s law, and whether the flow is laminar or turbulent. Parasympathetic stimulation causes bronchoconstriction and sympathetic stimulation causes bronchodilation, but mediated by beta2-adrenoceptors. Muscarinic antagonists e.g. ipratropium bromide cause bronchodilation.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 159
Incorrect
-
Regarding antacids, which of the following statements is CORRECT:
Your Answer:
Correct Answer: Antacids are contraindicated in hypophosphataemia.
Explanation:Antacids are contraindicated in hypophosphataemia. Liquid preparations are more effective than tablet preparations. Magnesium-containing antacids tend to be laxative whereas aluminium-containing antacids tend to be constipating. Antacids are best taken when symptoms occur or are expected, usually between meals and at bedtime. Antacids should preferably not be taken at the same time as other drugs since they may impair absorption.
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This question is part of the following fields:
- Gastrointestinal
- Pharmacology
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Question 160
Incorrect
-
A 74-year-old woman with a history of ischaemic heart disease and heart failure is complaining of worsening oedema, bloating, and a loss of appetite. She has ascites and peripheral oedema on examination. Her oedema is being controlled by an oral diuretic, but it appears that this is no longer enough. You discuss her care with the on-call cardiology registrar, who believes she is very likely to have significant gut oedema that is interfering with her diuretic absorption and that she will need to change her medication.
Which of the following oral diuretics is most likely to help you overcome this problem?Your Answer:
Correct Answer: Bumetanide
Explanation:Bumetanide is primarily used in patients with heart failure who have failed to respond to high doses of furosemide. Bumetanide and furosemide differ primarily in terms of bioavailability and pharmacodynamic potency. In the intestine, furosemide is only partially absorbed, with a bioavailability of 40-50 percent. Bumetanide, on the other hand, is almost completely absorbed in the intestine and has a bioavailability of about 80%. As a result, when it has a better bioavailability than furosemide, it is commonly used in patients with gut oedema.
When taken alone, Bendroflumethiazide is a moderately potent diuretic that is unlikely to control her oedema.
Mannitol is a type of osmotic diuretic used to treat cerebral oedema and high intracranial pressure.
Acetazolamide is a weak diuretic that inhibits carbonic anhydrase. It’s a rare occurrence.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 161
Incorrect
-
For the treatment of his atrial fibrillation, a 59-year-old man is about to begin taking warfarin. He also takes a number of other medications.
Which of the following medications will enhance warfarin's effects?Your Answer:
Correct Answer: Erythromycin
Explanation:Many medications, including warfarin, require cytochrome P450 enzymes for their metabolism. When co-prescribing cytochrome p450 enzyme inducers and inhibitors with warfarin, it’s critical to be cautious.
Inhibitors of the cytochrome p450 enzyme potentiate the effects of warfarin, resulting in a higher INR. To remember the most commonly encountered cytochrome p450 enzyme inhibitors, use the mnemonic O DEVICES:
O– Omeprazole
D– Disulfiram
E– Erythromycin (And other macrolide antibiotics)
V– Valproate (sodium valproate)
I– Isoniazid
C– Ciprofloxacin
E– Ethanol (acute ingestion)
S- Sulphonamides -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 162
Incorrect
-
An ambulance transports a 72-year-old woman to the Emergency Department. She is confused, has been vomiting and having stomach pains. Digoxin is one of her medications.
Which of the following claims about digoxin is correct?Your Answer:
Correct Answer: Therapeutic plasma levels are between 1.0-1.5 nmol/l
Explanation:Digoxin is a cardiac glycoside that is used to treat atrial fibrillation and flutter, as well as congestive heart failure. In cardiac myocytes, it works by inhibiting the membrane Na/K ATPase. Through Na/Ca exchange, this raises intracellular sodium concentration and indirectly increases intracellular calcium availability. Increased intracellular calcium levels have both a positive inotropic and negative chronotropic effect.
Digoxin therapeutic plasma levels are typically between 1.0 and 1.5 nmol/l, though higher concentrations may be required, and the value varies between laboratories. At concentrations greater than 2 nmol/l, the risk of toxicity increases dramatically.
In patients with normal renal function, digoxin has a long plasma half-life of 36 to 48 hours. This can take up to 5 days in patients with impaired renal function.
Hypokalaemia, rather than hyperkalaemia, has been shown to increase the risk of digoxin toxicity.
In the treatment of persistent and permanent atrial fibrillation, digoxin is no longer widely used. Beta-blockers, also known as rate-limiting calcium channel blockers, are now the first-line treatment for this condition.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 163
Incorrect
-
Regarding carbon dioxide transport in the blood, which of the following statements is CORRECT:
Your Answer:
Correct Answer: Deoxygenated haemoglobin acts as a buffer for H+ ions.
Explanation:CO2generated in the tissues and water combine to form carbonic acid which readily dissociates to form HCO3-and H+. The first part of this reaction is very slow in plasma, but is accelerated dramatically by the enzyme carbonic anhydrase present in red blood cells. Bicarbonate is therefore formed preferentially in red cells, from which it freely diffuses down its concentration gradient into plasma where it is transported to the lungs. The red cell membrane is impermeable to H+ions which remain in the cell. To maintain electroneutrality, Cl-ions diffuse into the cell to replace HCO3-, an effect known as the chloride shift. Deoxygenated haemoglobin acts as a buffer for H+, allowing the reaction to continue.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 164
Incorrect
-
A 55-year-old female is urgently rushed into the Emergency Department as she complains of chest pain that is worse on breathing, shortness of breath, palpitations, and haemoptysis.
She undergoes a CT pulmonary angiogram, which reveals a large pulmonary embolus. She is immediately started on heparin and shifted to the acute medical ward.
Which of the following does heparin activate?Your Answer:
Correct Answer: Antithrombin III
Explanation:Heparin works by binding to and activating the enzyme inhibitor antithrombin III.
Antithrombin III inactivates thrombin (factor IIa) by forming a 1:1 complex with thrombin. The heparin-antithrombin III complex also inhibits factor Xa and some other proteases involved with clotting. The heparin-ATIII complex can also inactivate IX, XI, XII, and plasmin.
Heparin is a polymer of glycosaminoglycan. It occurs naturally and is found in mast cells. Clinically, it is used in two forms:
1. Unfractionated: widely varying polymer chain lengths
2. Low molecular weight: Smaller polymers onlyHeparin is not thrombolytic or fibrinolytic. It prevents the progression of existing clots by inhibiting further clotting. The lysis of existing clots relies on endogenous thrombolytics.
Heparin is used for:
1. Prevention and treatment of venous thromboembolism
2. Treatment of disseminated intravascular coagulation
3. Treatment of fat embolism
4. Priming of haemodialysis and cardiopulmonary bypass machines -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 165
Incorrect
-
Amoxicillin is used first line for all of the following infections EXCEPT for:
Your Answer:
Correct Answer: Cellulitis
Explanation:Amoxicillin is used first line for low to moderate severity community acquired pneumonia, exacerbations of chronic bronchitis, for acute otitis media, for acute sinusitis, for oral infections/dental abscess, for Listeria meningitis (in combination with another antibiotic), for infective endocarditis (in combination with another antibiotic) and for H. Pylori eradication (in combination with metronidazole/clarithromycin and a PPI). Flucloxacillin is used first line for acute cellulitis.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 166
Incorrect
-
Regarding the management of diabetic ketoacidosis (DKA), insulin should initially be given:
Your Answer:
Correct Answer: At a concentration of 1 unit/mL at a fixed rate of 0.1 units/kg/hour
Explanation:An intravenous insulin infusion should be started at a concentration of 1 unit/mL, at a fixed rate of 0.1 units/kg/hour. Established subcutaneous long-acting insulin therapy should be continued concomitantly. Blood ketone and blood glucose concentrations should be checked hourly and the insulin infusion rate adjusted accordingly. Blood ketone concentration should fall by at least 0.5 mmol/litre/hour and blood glucose concentration should fall by at least 3 mmol/litre/hour.
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This question is part of the following fields:
- Endocrine
- Pharmacology
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Question 167
Incorrect
-
Following a phone call from the microbiology consultant, you evaluate a patient who has been diagnosed with urinary sepsis. Following the results of the blood cultures, he recommends that you add gentamicin to the patient's antibiotic treatment.
Gentamicin produces its pharmacological effect by binding to which of the following?Your Answer:
Correct Answer: The 30S subunit of the bacterial ribosome
Explanation:Antibiotics with aminoglycosides, such as gentamicin, bind to the 30S subunit of the bacterial ribosome and prevent aminoacyl-tRNA from binding, preventing protein synthesis.
They also cause mRNA misreading, resulting in the production of non-functional proteins. This last mechanism is unique to aminoglycosides, and it may explain why they are bactericidal rather than bacteriostatic, as other protein synthesis inhibitors are.
Patients with myasthenia gravis should avoid aminoglycosides since they can disrupt neuromuscular transmission. They cross the placenta and are linked to poisoning of the 8th cranial nerve in the foetus, as well as permanent bilateral deafness.
It is possible that they will cause deafness, although this is not a contraindication. In individuals with renal impairment, serum aminoglycoside concentrations should be closely monitored, but this is still not considered a contraindication.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 168
Incorrect
-
A 4-year-old girl is rushed to the Emergency Department by her grandparents after swallowing some of her grandfather's Warfarin tablets. On further questioning, it turns out that she took 5 of his 3 mg tablets which he needs to take due to a history of atrial fibrillation. The child appears healthy well-oriented in time, place and person, and has normal vitals.
What is the threshold dose of Warfarin that needs to be ingested for there to be a risk of anticoagulation?Your Answer:
Correct Answer: 0.5 mg/kg
Explanation:The clinical effects of Warfarin occur after a dose of greater than 0.5 mg/kg, and they will be observable 8-10 hours after consumption of the drug. The antidote used for Warfarin is Vitamin K.
1. In low-risk cases with no apparent bleeding:
an oral dose of 10 mg vitamin K2. If there is clinically significant bleeding
an intravenous dose of 250-300 mcg/kgActivated charcoal:
in cases of warfarin ingestion
binds to it and reduces the absorption of warfarin
the ingestion must have occurred within the last hour
There is, however, rarely a need for the use of activated charcoal because vitamin K is such as safe and effective antidote.Clotting studies, including an INR, can be performed, but small children who have ingested warfarin do not require INRs or follow up if they have been treated with 10 mg vitamin K. This dose of vitamin will completely reverse the anticoagulative effects of warfarin.
Perform INR if any of the following are present:
1. Delayed presentation (>6 hours)
2. Patients with symptoms or signs of anticoagulation
3. Possible massive ingestion -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 169
Incorrect
-
A known epileptic is transported in status epilepticus by ambulance. On the way to the hospital, she took some diazepam.
Which of the following statements about diazepam is correct?Your Answer:
Correct Answer: It crosses into breast milk
Explanation:Diazepam boosts GABA’s effects, giving it sedative, hypnotic, anxiolytic, anticonvulsant, and muscle-relaxing properties. It can be administered orally, rectally, or intravenously.
With a half-life of 20-100 hours, it is a long-acting benzodiazepine. Midazolam, oxazepam, and alprazolam are examples of short-acting benzodiazepines with a half-life of less than 12 hours (Xanax).
If used in the presence of hepatic impairment, benzodiazepines can cause coma. If treatment is necessary, benzodiazepines with shorter half-lives should be used in lower doses. Diazepam is a sedative that crosses into breast milk and should be avoided by breastfeeding mothers.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 170
Incorrect
-
Regarding V/Q mismatch, which of the following statements is CORRECT:
Your Answer:
Correct Answer: In a true shunt, increasing inspired oxygen has no effect on improving hypoxaemia.
Explanation:Both ventilation and perfusion increase towards the lung base, because of the effects of gravity, but the gravitational effects are greater on perfusion than ventilation and therefore there is a regional variation in V/Q ratio from lung apex (high V/Q) to lung base (low V/Q). In a pure shunt, there is normal perfusion but absent ventilation and the V/Q ratio = 0. In a true shunt increasing oxygen fraction has no effect because the oxygen-enriched air fails to reach the shunted blood. An increased A-a gradient is seen in V/Q mismatch.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 171
Incorrect
-
Flucloxacillin is used first line for all of the following infections EXCEPT for:
Your Answer:
Correct Answer: Otitis media
Explanation:Flucloxacillin is used first line for treatment of widespread impetigo infection, cellulitis, mastitis, osteomyelitis, septic arthritis, severe erysipelas, severe/spreading otitis externa and infective endocarditis caused by staphylococci. Amoxicillin is first line for acute otitis media.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 172
Incorrect
-
Following an injury sustained during a rugby match, a 16-year-old boy is brought to the Emergency Department by his mother. His forearm appears to be deformed, and you believe he has a distal radius fracture. A numerical rating scale is used to assess his pain, and the triage nurse informs you that he is in moderate pain.'
The RCEM guidance recommends which of the following analgesics for the treatment of moderate pain in a child of this age?Your Answer:
Correct Answer: Oral codeine phosphate 1 mg/kg
Explanation:According to a 2018 audit conducted by the Royal College of Emergency Medicine (RCEM), the standard of care for children presenting to EDs with fractured limbs has deteriorated, with most patients waiting longer than ever before for pain relief. More than one-tenth of the children who came in with significant pain from a limb fracture received no pain relief at all.
For all patients, including children, the Agency for Health Care Policy and Research (AHCPR) in the United States recommends using the ABCs of pain management:
A – Ask about pain regularly. Assess pain systematically.
B – Believe the patient and family in their reports of pain and what relieves it.
C – Choose pain control options appropriate for the patient, family, and setting.
D – Deliver interventions in a timely, logical, coordinated fashion.
E – Empower patients and their families. Enable patients to control their course to the greatest extent possible.The RCEM guidelines recommend assessing a child’s pain within 15 minutes of arrival. This is a fundamental requirement. For the assessment of pain in children, a variety of rating scales are available; which one is used depends on the child’s age and ability to use the scale. These are some of them:
Faces of Wong-Baker Scale for assessing pain
Scale of numerical evaluation
The behavioural scale is a scale that measures how people behave.The RCEM has provided the following visual guide:
The RCEM has established the following guidelines for when patients in severe pain should receive appropriate analgesia:
100% within 60 minutes of arrival or triage, whichever is earliest
75% within 30 minutes of arrival or triage, whichever is earliest
50% within 20 minutes of arrival or triage, whichever is earliest -
This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 173
Incorrect
-
Antispasmodic drugs are primarily indicated in which of the following conditions:
Your Answer:
Correct Answer: Irritable bowel syndrome
Explanation:Antispasmodics, such as antimuscarinics, may be used in the management of irritable bowel syndrome. Other antispasmodics used include direct-acting smooth muscle relaxants such as mebeverine, alverine, and peppermint oil. Antispasmodics are contraindicated in bowel obstruction and severe inflammatory bowel disease. Antispasmodics are occasionally of value in treating abdominal cramp associated with diarrhoea but they should not be used for primary treatment. Antispasmodics should be avoided in young children with gastroenteritis because they are rarely effective and have troublesome side effects. Antimuscarinics are contraindicated in urinary retention.
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This question is part of the following fields:
- Gastrointestinal
- Pharmacology
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Question 174
Incorrect
-
Which of the following is caused by an alpha-1 antitrypsin deficiency?
Your Answer:
Correct Answer: Early onset emphysema
Explanation:Mucus contains chemicals such as alpha-1-antitrypsin, lysozyme, and IgA that protect the airway from pathogens and damaging proteases released from dead bacteria and immune cells. Early-onset emphysema results from a genetic deficit of alpha-1-antitrypsin, which is caused by unregulated protease activity in the lungs, which results in the degradation of elastin in the alveoli.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 175
Incorrect
-
Regarding nitrous oxide, which of the following statements is CORRECT:
Your Answer:
Correct Answer: Nitrous oxide may be used for maintenance of anaesthesia where its use allows reduced dosage of other agents.
Explanation:For anaesthesia, nitrous oxide is commonly used in a concentration of around 50 – 66% in oxygen in association with other inhalation or intravenous agents. Nitrous oxide cannot be used as the sole anaesthetic agent due to lack of potency, but is useful as part of a combination of drugs since it allows reduction in dosage of other agents. Exposure to nitrous oxide for prolonged periods, either by continuous or by intermittent administration, may result in megaloblastic anaemia as a result of interference with the action of vitamin B12. Nitrous oxide increases cerebral blood flow and should be avoided in patients with, or at risk of, raised intracranial pressure. Nitrous oxide may be administered by any trained personnel experienced in its use.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 176
Incorrect
-
A 28-year-old patient who has been in a car accident needs to be intubated using a rapid sequence induction. As an induction agent, you intend to use etomidate.
Etomidate works by interacting with which type of receptor?Your Answer:
Correct Answer: Gamma-aminobutyric acid (GABA)
Explanation:Etomidate is a carboxylated imidazole derivative with a short half-life that is primarily used to induce anaesthesia.
It is thought to modulate fast inhibitory synaptic transmission in the central nervous system by acting on GABA type A receptors.
The dose for anaesthesia induction is 0.3 mg/kg. Etomidate takes 10-65 seconds to take effect after an intravenous injection, and it lasts 6-8 minutes. With repeated administration, the effects are non-cumulative.The relative cardiovascular stability of etomidate is noteworthy. During induction, it causes less hypotension than thiopental sodium and propofol. It’s also linked to a quick recovery without the hangover.
Etomidate is a strong steroidogenesis inhibitor. The drug inhibits the enzymes responsible for adrenal 11 beta-hydroxylase and cholesterol cleavage, resulting in a decrease in cortisol and aldosterone synthesis for up to 24 hours after administration. It should not be used to maintain anaesthesia because of the adrenocortical suppression.
Other side effects associated with etomidate use include:
Vomiting and nausea
The injection causes pain (in up to 50 percent )
Phlebitis and thrombosis of the veins
Heart block and arrhythmias
Hyperventilation
Apnoea and respiratory depression
It has the potential to cause both hypo- and hypertension.
Critically ill patients have a higher mortality rate. -
This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 177
Incorrect
-
Regarding antimuscarinic antispasmodics, which of the following statements is CORRECT:
Your Answer:
Correct Answer: They are contraindicated in paralytic ileus.
Explanation:Antimuscarinics are contraindicated in paralytic ileus. Antimuscarinics reduce intestinal motility by blocking muscarinic acetylcholine receptors and relaxing smooth muscle. Hyoscine butylbromide is advocated as a gastrointestinal antispasmodic, but it is poorly absorbed and thus has limited clinical utility. Antimuscarinics cause a reduction in bronchial secretions (they can be used to this effect in palliative patients). Antispasmodics are occasionally of value in treating abdominal cramp associated with diarrhoea but they should not be used for primary treatment. Antispasmodics should be avoided in young children with gastroenteritis because they are rarely effective and have troublesome side effects.
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This question is part of the following fields:
- Gastrointestinal
- Pharmacology
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Question 178
Incorrect
-
A 52-year-old woman visits her local pharmacy to get medication to help with mild dyspepsia symptoms. The pharmacist on duty suggests she uses an over-the-counter antacid. She purchases an antacid that contains magnesium carbonate, which relieves her symptoms, but she unfortunately also develops a side effect.
Out of the following, which side effect is she MOST likely to develop after using the antacid?Your Answer:
Correct Answer: Diarrhoea
Explanation:Magnesium carbonate is an over the counter antacid commonly used to relieve symptoms in ulcer dyspepsia and non-erosive gastro-oesophageal reflux.
Antacids containing magnesium also tend to work as a laxative, while the antacids with aluminium may cause constipation. There is no significant increased risk of anaphylaxis, hepatotoxicity or renal impairment.
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This question is part of the following fields:
- Gastrointestinal Pharmacology
- Pharmacology
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Question 179
Incorrect
-
Regarding gas exchange at the alveolar-capillary membrane, which of the following statements is CORRECT:
Your Answer:
Correct Answer: The rate of diffusion in lungs can be estimated by measuring the diffusing capacity of the lungs for carbon monoxide.
Explanation:Gas exchange between alveolar air and blood in the pulmonary capillaries takes place by diffusion across the alveolar-capillary membrane. Diffusion occurs from an area of high partial pressure to an area of low partial pressure, thus the driving force for diffusion is the alveolar-capillary partial pressure gradient. Diffusion occurs across a membrane and is therefore governed by Fick’s law. Although CO2is larger than O2, it is is much more soluble and diffuses 20 times more rapidly. The diffusing capacity for oxygen (DLO2) cannot be measured directly but the rate of diffusion in the lungs can be estimated by measuring the diffusing capacity of the lungs for carbon monoxide (DLCO).
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 180
Incorrect
-
A 45-old woman is on several medications and being treated for epilepsy and bipolar disorder. In the ward rounds, you are asked to examine her in detail and discover she has a noticeable tremor. You believe that one of her medications may be responsible for this new onset tremor.
Which of the following medications is least likely to be responsible for this tremor?Your Answer:
Correct Answer: Carbamazepine
Explanation:The only medication that does not commonly cause tremors is carbamazepine.
The other drugs present with the following types of tremors as a side effect to their usage:
1. Sodium valproate – Postural tremor is most common, but a resting tremor can also occur. Approximately 25% of patients taking sodium valproate are found to develop a tremor within 12 months of starting therapy.
2. Lithium – fine hand tremor is very commonly seen and reported in as many as 50% of patients during the first week of therapy. The tremor tends to reduce with time and is only present in around 5% of patients taking the medication two years or longer.
3. Atypical antipsychotics, such as olanzapine and quetiapine – tremor and limb shakiness. -
This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 181
Incorrect
-
A 68-year-old female has presented to the Emergency Department with chest pain, palpitations, and breathlessness complaints. On ECG, she is diagnosed with ventricular arrhythmia and is administered lidocaine.
Which of the following is the correct mechanism of action of lidocaine?Your Answer:
Correct Answer: Blocks Na+ channels in the heart
Explanation:Lidocaine is a tertiary amide local anaesthetic and also a class IV antiarrhythmic.
Like other local anaesthetics, lidocaine works on the voltage-gated sodium ion channel on the nerve cell membranes. It works in the following steps:
1. diffuses through neural sheaths and the axonal membrane into the axoplasm
2. binds fast voltage-gated Na+ channels in the neuronal cell membrane and inactivates them
3. With sufficient blockage, the membrane of the postsynaptic neuron will not depolarise and will be unable to transmit an action potential, thereby preventing the transmission of pain signalsThe same principle applies to Lidocaine’s actions in the heart as it blocks the sodium channels in the conduction system and the myocardium. This raises the threshold for depolarizing, making it less likely for the heart to initiate or conduct any action potential that can cause arrhythmia.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 182
Incorrect
-
A 34-year-old male presents to the Emergency Department with the complaint of palpitations and difficulty breathing, which started suddenly half an hour ago. His ECG shows findings of supraventricular tachycardia. You attempt vagal manoeuvres but cannot convert them back to sinus rhythm. Therefore, drug therapy is necessary to terminate the arrhythmia. Adenosine cannot be used in this patient because of a contra-indication listed in his medical record.
Which one of the conditions listed below would be a contraindication in this case?Your Answer:
Correct Answer: Asthma
Explanation:Entonox is a mixture of 50% Oxygen and 50% nitrous oxide and is given in an inhaled form as a quick form of analgesia. Entonox causes non-competitive inhibition of NMDA (N-methyl-D-aspartate) receptors, which are a subtype of the glutamate receptor.
It is stored in blue and white cylinders and administered via a pressure regulator and demand valve. The administration of this medicine reduces pain and anxiety in paediatric and dental procedures ands during labour.
Effects are apparent after 20 seconds, and peak action occurs after 3 to 5 minutes as it is a drug with a rapid onset and the patient will also recover rapidly from its effects. Entonox is widely used as it does not accumulate in the body and does not cause many side effects. However, a notable side effect is the inhibition of Vitamin B12 synthesis.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 183
Incorrect
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Regarding benzylpenicillin, which of the following statements is CORRECT:
Your Answer:
Correct Answer: If meningococcal disease is suspected, benzylpenicillin should be given before transfer to hospital.
Explanation:Benzylpenicillin (although inactivated by bacterial beta-lactamases) is effective for many streptococcal (including pneumococcal), gonococcal, and meningococcal infections and also for anthrax, diphtheria, gas gangrene, leptospirosis, and treatment of Lyme disease. If meningococcal disease (meningitis with non-blanching rash or meningococcal septicaemia) is suspected, benzylpenicillin should be given before transfer to hospital, so long as this does not delay the transfer; benzylpenicillin is no longer the drug of first choice for pneumococcal meningitis. Although benzylpenicillin is effective in the treatment of tetanus, metronidazole is preferred. Benzylpenicillin is inactivated by gastric acid and absorption from the gastrointestinal tract is poor and therefore it must be given by injection.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 184
Incorrect
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In a ward round, you come across a patient's treatment chart prescribed an antibiotic to fight his infection. This antibiotic is an inhibitor of cell wall synthesis.
Which of the following antimicrobial drugs is prescribed to this patient?Your Answer:
Correct Answer: Benzylpenicillin
Explanation:Penicillins and cephalosporins are the major antibiotics that inhibit bacterial cell wall synthesis. They inactivate transpeptidases that help cross-link peptidoglycans in cell walls.
Isoniazid decreases the synthesis of mycolic acids in mycobacterium.
Clarithromycin binds to the 50S subunit of ribosomes and inhibits protein synthesis.
Metronidazole and the other 5-nitroimidazole agents inhibit nucleic acid synthesis by forming toxic free radical metabolites in the bacterial cell that damage DNA.
Tetracycline bind to 30S and prevent attachment of aminoacyl-tRNA.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 185
Incorrect
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You've been summoned to the resuscitation area to assist a patient who is having a seizure. As part of the treatment protocol, a benzodiazepine dose is given.
Which of the following statements about the use of benzodiazepines in seizures is correct?Your Answer:
Correct Answer: Lorazepam can be given by the rectal route
Explanation:A single dose of IV benzodiazepine will terminate the seizure in 60 to 80 percent of patients who present with seizures.
Because benzodiazepines are lipid-soluble, they cross the blood-brain barrier quickly. This explains their quick onset of action.
As a first-line treatment, IV lorazepam should be given. If IV lorazepam is not available, IV diazepam can be used instead, and buccal midazolam can be used if intravenous access cannot be established quickly. Lorazepam can be administered via the rectal route, but it is less reliable and has a lower absorption rate and bioavailability.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 186
Incorrect
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A 34-year-old man arrives at the department befuddled. He has a history of schizophrenia and is on an antipsychotic medication, but he can't recall what it's called.
Which of the following statements about antipsychotic drug side effects is correct?Your Answer:
Correct Answer: Haloperidol is the most common causative antipsychotic drug
Explanation:Extrapyramidal side effects are most common with piperazine phenothiazines (fluphenazine, prochlorperazine, and trifluoperazine) and butyrophenones (fluphenazine, prochlorperazine, and trifluoperazine) (benperidol and haloperidol). The most common causative antipsychotic drug is haloperidol.
Tardive dyskinesia (rhythmic, involuntary movements of the tongue, face, and jaw) is most commonly associated with long-term or high-dose treatment. It is the most serious form of extrapyramidal symptoms because withdrawal of the causative drug may make it irreversible, and treatment is usually ineffective.
Dystonia (abnormal facial and body movements) is more common in children and young adults, and it usually shows up after only a few doses. Procyclidine 5 mg IV or benzatropine 2 mg IV as a bolus can be used to treat acute dystonia.
An unpleasant feeling of restlessness characterises akathisia. The inability to initiate movement is known as akinesia.
Renal impairment causes increased cerebral sensitivity, so lower doses should be used.
In elderly patients with dementia-related psychosis who are treated with haloperidol, there is an increased risk of death. This appears to be due to a higher risk of heart attacks and infections like pneumonia.
The following are some of the antipsychotic drugs’ contraindications:
Reduced level of consciousness/coma
Depression of the central nervous system
Phaeochromocytoma -
This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 187
Incorrect
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Dysuria and urinary frequency are symptoms of a 29-year-old woman. A urine dipstick is used to detect the presence of blood, protein, leucocytes, and nitrites in the urine. You diagnose a urinary tract infection and give antibiotics to the patient.
In the United Kingdom, which of the following antibiotics has the highest percentage of E.coli resistance?Your Answer:
Correct Answer: Trimethoprim
Explanation:In the United Kingdom, antibiotic resistance is becoming a significant factor in the treatment of urinary tract infections and pyelonephritis. E. coli (the main causative organism of both urinary tract infections and acute pyelonephritis) resistance to the following antibiotics in laboratory-processed urine specimens is:
30.3 percent trimethoprim (varies by area from 27.1 to 33.4 percent )
19.8 percent co-amoxiclav (varies by area from 10.8 to 30.7 percent )
Ciprofloxacin (Cipro): 10.6% (varies by area from 7.8 to 13.7 percent )
Cefalexin has a concentration of 9.9%. (varies by area from 8.1 to 11.4 percent ) -
This question is part of the following fields:
- Infections
- Pharmacology
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Question 188
Incorrect
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During the second and third trimesters of her pregnancy, a 36-year-old woman is given a drug to treat a medical condition. The foetus has developed hypoperfusion and the oligohydramnios sequence as a result of this.
Which of the following drugs is most likely to be the cause of these side effects?Your Answer:
Correct Answer: Ramipril
Explanation:Hypoperfusion, renal failure, and the oligohydramnios sequence are all linked to ACE inhibitor use in the second and third trimesters.
The oligohydramnios sequence refers to a foetus’ or neonate’s atypical physical appearance as a result of oligohydramnios in the uterus. It’s also linked to aortic arch obstructive malformations and patent ductus arteriosus.
The inhibitory effects on the renin-angiotensin-aldosterone system appear to be the cause of these defects. To avoid these risks, ACE inhibitors should be stopped before the second trimester.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 189
Incorrect
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A 63 year old lady presents to ED with a persistent cough and red currant jelly sputum. She has a history of chronic alcohol abuse and has an X-ray which demonstrates a cavitating pneumonia. The most likely causative pathogen is:
Your Answer:
Correct Answer: Klebsiella pneumoniae
Explanation:One of the results of Klebsiella pneumoniae is pneumonia that is usually a very severe infection. It is characterised by thick, bloody sputum (red currant jelly sputum), and is associated with complications like lung abscess, cavitation, necrosis, empyema and pleural effusions.
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This question is part of the following fields:
- Infections
- Microbiology
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Question 190
Incorrect
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Which of the following is an action of glucagon:
Your Answer:
Correct Answer: Stimulates glycogenolysis
Explanation:Glucagon is a peptide hormone that is produced and secreted by alpha cells of the islets of Langerhans, which are located in the endocrine portion of the pancreas. The main physiological role of glucagon is to stimulate hepatic glucose output, thereby leading to increases in glycaemia. It provides the major counter-regulatory mechanism to insulin in maintaining glucose homeostasis.
Hypoglycaemia is the principal stimulus for the secretion of glucagon but may also be used as an antidote in beta-blocker overdose and in anaphylaxis in patients on beta-blockers that fail to respond to adrenaline.
Glucagon then causes:
Glycogenolysis
Gluconeogenesis
Lipolysis in adipose tissue
The secretion of glucagon is also stimulated by:
Adrenaline
Cholecystokinin
Arginine
Alanine
Acetylcholine
The secretion of glucagon is inhibited by:
Insulin
Somatostatin
Increased free fatty acids
Increased urea productionGlycolysis is the metabolic pathway that converts glucose into pyruvate. The free energy released by this process is used to form ATP and NADH. Glycolysis is inhibited by glucagon, and glycolysis and gluconeogenesis are reciprocally regulated so that when one cell pathway is activated, the other is inactive and vice versa.
Glucagon has a minor effect of enhancing lipolysis in adipose tissue. Lipolysis is the breakdown of lipids and involves the hydrolysis of triglycerides into glycerol and free fatty acids. It makes fatty acids available for oxidation.
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This question is part of the following fields:
- Endocrine
- Pharmacology
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Question 191
Incorrect
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A 42-year-old patient with worsening epigastric pain has been referred to you by a GP. The patient has been taking omeprazole for a month, but her symptoms are getting worse.
Which of the following is NOT a well-known side effect of proton pump inhibitor treatment?Your Answer:
Correct Answer: Pelvic fracture
Explanation:Proton pump inhibitors (PPIs) have a variety of side effects, including:
Vomiting and nausea
Pain in the abdomen
Flatulence
Diarrhoea
Constipation
HeadachePPIs have been linked to a significant increase in the risk of focal tachyarrhythmias (link is external).
Low serum magnesium and sodium levels have been linked to long-term use of PPIs, according to the US Food and Drug Administration (link is external).Long-term PPI use has also been linked to an increased risk of fracture, according to epidemiological evidence (link is external). Observational studies have discovered a slight link between hip, wrist, and spine fractures. However, there is no link between the two and an increased risk of pelvic fracture. For this reason, the MHRA recommends that patients at risk of osteoporosis who take PPIs maintain an adequate calcium and vitamin D intake.
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This question is part of the following fields:
- Gastrointestinal Pharmacology
- Pharmacology
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Question 192
Incorrect
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A 61-year-old man complains of crushing chest pain that radiates to his left arm and jaw. An ECG is taken, and the lateral leads show extensive ST depression. His blood pressure is currently 190/123 mmHg, and as part of his treatment, you intend to begin drug therapy to lower it.
Which of the following is the INITIAL drug treatment for this patient's BP reduction?Your Answer:
Correct Answer: Glyceryl trinitrate
Explanation:End-organ damage (e.g. encephalopathy, intracranial haemorrhage, acute myocardial infarction or ischaemia, dissection, pulmonary oedema, nephropathy, eclampsia, papilledema, and/or angiopathic haemolytic anaemia) characterises a hypertensive emergency (also known as ‘accelerated hypertension’ or malignant hypertension’ It’s a life-threatening condition that necessitates rapid blood pressure reduction to avoid end-organ damage and a negative outcome.
In the presence of cardiac ischaemia, hypertensive emergencies require immediate treatment to prevent myocardial infarction.
Similarly, if myonecrosis occurs in the presence of an existing infarction, prompt treatment is required to prevent further myonecrosis. When thrombolysis is used as the primary reperfusion therapy for acute myocardial infarction, blood pressure control is especially important.
An intravenous nitrate is the drug of choice in this situation (e.g. GTN). These have a dual purpose in that they can help patients with ischaemic chest pain manage their symptoms. Because lowering blood pressure with nitrates isn’t always enough to achieve optimal results, intravenous beta-blockers are frequently used as a supplement. For this, intravenous atenolol and metoprolol are commonly used.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 193
Incorrect
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Due to severe palpitations, a 28-year-old woman is transported to the Emergency Department by ambulance. Her heart rate is 180 beats per minute, and the rhythm strip shows supraventricular tachycardia. You intend to give adenosine.
Which of the following is NOT a contraindication for adenosine use?Your Answer:
Correct Answer: History of heart transplant
Explanation:The purine nucleoside adenosine is used to diagnose and treat paroxysmal supraventricular tachycardia. Adenosine works by stimulating A1-adenosine receptors and opening potassium channels that are sensitive to acetylcholine. This causes the atrioventricular (AV) node’s cell membrane to become hyperpolarized, slowing conduction by inhibiting calcium channels.
Patients who have had a heart transplant are extremely sensitive to the effects of adenosine and should start with a lower dose of 3 mg, then 6 mg, and finally 12 mg. Dipyridamole potentiates the effects of adenosine, so it should be used with caution in patients who are taking it.
The use of adenosine is contraindicated in the following situations:
Asthma
COPD (chronic obstructive pulmonary disease)
Decompensated heart failure
Long QT syndrome
AV block in the second or third degree
Sinusitis is a condition in which the sinuses become (unless pacemaker fitted)
Hypotension that is severeIt has a half-life of less than 10 seconds and acts quickly within that time frame. The actions last between 10 and 20 seconds.
Because of the short half-life of the drug, any side effects are usually only temporary. These are some of them:
a feeling of impending doom
Flushing of the face
Dyspnoea
Uncomfortable chest
Tastes metallic -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 194
Incorrect
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Regarding flucloxacillin, which of the following statements is CORRECT:
Your Answer:
Correct Answer: It is resistant to bacterial beta-lactamases.
Explanation:Flucloxacillin is unique in that it is beta-lactamase stable and it can be used in infections caused by beta-lactamase producing staphylococci e.g. S. aureus. It is acid-stable and can therefore be given by mouth as well as by injection. It is used first line for treatment of widespread impetigo infection, cellulitis, mastitis, osteomyelitis, septic arthritis, severe erysipelas, severe/spreading otitis externa and infective endocarditis caused by staphylococci. The most common adverse effects of flucloxacillin include nausea, vomiting, skin rash, and diarrhoea. Cholestatic jaundice and hepatitis may occur very rarely, up to two months after treatment with flucloxacillin has been stopped. Administration for more than 2 weeks and increasing age are risk factors. First line treatment of animal and human bites is co-amoxiclav.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 195
Incorrect
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You are instructed by a senior to administer Mannitol to an RTA patient with increased intracranial pressure.
Mannitol is a low molecular weight compound that freely filters at the glomerulus and is not reabsorbed.
Out of the following, which is a contraindication to the use of mannitol?Your Answer:
Correct Answer: Severe pulmonary oedema
Explanation:Mannitol is the most widely used osmotic diuretic that is most commonly used to reduce cerebral oedema and intracranial pressure.
It is recommended to use mannitol for the reduction of CSF pressure/cerebral oedema in a dose of 0.25-2 g/kg as an intravenous infusion over 30-60 minutes. This can be repeated 1-2 times after 4-8 hours if needed.Mannitol has several contraindications and some of them are listed below:
1. Anuria due to renal disease
2. Acute intracranial bleeding (except during craniotomy)
3. Severe cardiac failure
4. Severe dehydration
5. Severe pulmonary oedema or congestion
6. Known hypersensitivity to mannitol -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 196
Incorrect
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Which of the following is NOT a mineralocorticoid effect of corticosteroids:
Your Answer:
Correct Answer: Hyperglycaemia
Explanation:Mineralocorticoid side effects include:hypertensionsodium retentionwater retention and oedemapotassium losscalcium loss
Glucocorticoid side effects include:weight gainhyperglycaemia and diabetesosteoporosis and osteoporotic fracturesmuscle wasting (proximal myopathy)peptic ulceration and perforationpsychiatric reactions -
This question is part of the following fields:
- Endocrine
- Pharmacology
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Question 197
Incorrect
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Which of the following statements about propofol is TRUE:
Your Answer:
Correct Answer: Propofol has some antiemetic action.
Explanation:Propofol has some antiemetic properties. It’s for this reason that it’s used to treat postoperative nausea and vomiting. Propofol is mostly processed in the liver, with the kidneys excreting just around 1% of it unaltered. Propofol, unlike thiopental, does not produce tissue necrosis when it is extravasated. Propofol lowers intracranial pressure via lowering brain metabolic rate and cerebral blood flow. Propofol is thought to be safe for people with bronchial asthma and chronic obstructive pulmonary disease.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 198
Incorrect
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The following all cause a left shift in the oxygen dissociation curve EXCEPT for:
Your Answer:
Correct Answer: Decrease in pH
Explanation:An increased affinity of haemoglobin for oxygen, shown by a left shift in the oxygen dissociation curve, is caused in the lungs by a rise in pH, a fall in PCO2,a decrease in temperature and a decrease in 2,3 -DPG. Carbon monoxide (CO) binds 240 times more strongly than O2to haemoglobin and by occupying O2-binding sites, reduces oxygen capacity. CO also increases oxygen affinity, shifting the oxygen haemoglobin curve to the left and making O2release to tissues more difficult.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 199
Incorrect
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A 50-year-old man presents with signs and symptoms of an anaphylactic reaction. His GP had recently given him a new medication.
Which one of these is the most likely medication responsible for the drug-induced anaphylactic reaction?
Your Answer:
Correct Answer: Penicillin
Explanation:The most common cause of drug-induced anaphylaxis is penicillin.
The second commonest cause are NSAIDs. Other drugs associated with anaphylaxis are ACE inhibitors and aspirin.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 200
Incorrect
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A 67-year-old man complains of chest pain and goes to the emergency room. He takes several medications, including amiodarone.
Which of the following is amiodarone mechanism of action?Your Answer:
Correct Answer: Blocks Na + and K + channels and beta-adrenoreceptors in the heart
Explanation:Amiodarone is an anti-arrhythmic medication that can be used to treat both ventricular and atrial arrhythmias. It’s a class III anti-arrhythmic that works by blocking a variety of channels, including Na+ and K+ channels, as well as beta-adrenoreceptors. As a result, it slows conduction through the SA and AV nodes and prolongs phase 3 of the cardiac action potential (slowing repolarisation).
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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SESSION STATS - PERFORMANCE PER SPECIALTY
