-
Question 1
Correct
-
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: 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.
-
This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
-
-
Question 2
Correct
-
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: 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
-
-
Question 3
Incorrect
-
You review a 56-year-old man who has recently been prescribed antibiotics for a chest infection. He suffers from COPD and is currently prescribed salbutamol and Seretide inhalers, and Phyllocontin continus. Since starting the antibiotics, he has been experiencing nausea, vomiting and abdominal pain.
Which of the following antibiotics is he MOST LIKELY to have been prescribed for his chest infection? Select ONE answer only .Your Answer: Amoxicillin
Correct Answer: Levofloxacin
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
-
-
Question 4
Correct
-
A 22-year-old presents with acute severe asthma. He takes a drug prescribed by her GP but cannot recall the name and is receiving regular salbutamol nebulisers. His current potassium level is 2.8 mmol/l.
Which drug is least likely to have caused his hypokalaemia?
Your Answer: Spironolactone
Explanation:Serious hypokalaemia can occur in severe asthma and the effect can be potentiated by concomitant treatment with theophyllines like aminophylline, corticosteroids, thiazide and loop diuretics, and hypoxia. Plasma-potassium concentration should be monitored in severe asthma.
Spironolactone, a potassium-sparing diuretic, is not likely to have contributed to patients hypokalaemia.
-
This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
-
-
Question 5
Correct
-
A 52-year-old female visits the Emergency Department complaining of an acute worsening of her asthma symptoms. A detailed history reveals that she took one of her brother's heart pills without a prescription as she was experiencing palpitations and thought it would cure her. Her shortness of breath was suddenly exacerbated after ingesting this medicine.
Which one of the following medications has this woman most likely consumed?Your Answer: Propranolol
Explanation:Propranolol, like other non-selective beta-blockers, is contraindicated in patients with asthma. These drugs can cause acute bronchospasm, therefore worsening symptoms, especially in high doses. However, there has been some recent evidence that long-term use of selective beta-blockers in mild or moderate asthma patients can be safe.
-
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 6
Correct
-
A 58-year-old man with a long history of depression presents with a deliberate overdose of verapamil tablets, which he is prescribed for a heart condition.
What is verapamil's mechanism of action?Your Answer: L-type calcium channel blockade
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 standard ABC approach should be used to resuscitate all patients as needed. If life-threatening toxicity is expected, intubation and ventilation should be considered early on. If hypotension and shock are developing, early invasive blood pressure monitoring is recommended.
The primary goal of specific treatments is to support the cardiovascular system. These are some of them:
1. Fluid resuscitation: Give up to 20 mL of crystalloid per kilogramme of body weight.
2. Calcium supplementation
This can be a good way to raise blood pressure and heart rate temporarily.
via central venous access: 10% calcium gluconate 60 mL IV (0.6-1.0 mL/kg in children) or 10% calcium chloride 20 mL IV (0.2 mL/kg in children)
Boluses can be given up to three times in a row.
To keep serum calcium >2.0 mEq/L, consider a calcium infusion.3. Atropine: 0.6 mg every 2 minutes up to 1.8 mg is an option, but it is often ineffective.
4. HIET (high-dose insulin-euglycemic therapy):
The role of HIET in the step-by-step management of cardiovascular toxicity has changed.5. Vasoactive infusions:
This was once thought to be a last-ditch measure, but it is now widely recommended that it be used sooner rather than later.
Insulin with a short half-life 50 mL of 50 percent glucose IV bolus plus 1 U/kg bolus (unless marked hyperglycaemia present)
Short-acting insulin/dextrose infusions should be continued.
Glucose should be checked every 20 minutes for the first hour, then hourly after that.
Regularly check potassium levels and replace if they fall below 2.5 mmol/L.
Titrate catecholamines to effect (inotropy and chronotropy); options include dopamine, adrenaline, and/or noradrenaline infusions.6. Sodium bicarbonate: Use 50-100 mEq sodium bicarbonate (0.5-1.0 mEq/kg in children) in cases where a severe metabolic acidosis develops.
7. Cardiac pacing: It can be difficult to achieve electrical capture, and it may not improve overall perfusion.
Bypass AV blockade with ventricular pacing, which is usually done at a rate of less than 60 beats per minute.8. Intralipid transport
Calcium channel blockers are lipid-soluble agents, so they should be used in refractory cases. -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 7
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
-
-
Question 8
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
-
-
Question 9
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.
-
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 10
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.
-
This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
-
-
Question 11
Incorrect
-
A 7-year-old presented to a GP with a history of headache, neck stiffness and photophobia. On examination, HR is 122, BP is 87/42, RR is 28, SaO 2 is 95%, temperature is 39.4 o C. There is a recent non-blanching rash on legs and arms. The GP administered a dose of antibiotics before transferring child to the Emergency Department.
Which of these is the most appropriate antibiotic to administer in this scenario from the choices available?
Your Answer:
Correct Answer: Give IM benzylpenicillin 600 mg
Explanation:Meningococcal septicaemia should be suspected in a child with a non-blanching rash especially in the presence of:
An ill-looking child
Neck stiffness
Lesions larger than 2 mm in diameter (purpura)
Capillary refill time of>3 secondsThe index child is very sick and shows signs of septic shock. In the prehospital setting, a single dose of benzylpenicillin should be given immediately. The correct dose for this childs age is IM benzylpenicillin 600 mg.
The recommended doses of benzylpenicillin according to age are:
Infants <1 year of age: IM or IV benzylpenicillin 300 mg
Children 1 to 9 years of age: IM or IV benzylpenicillin 600mg
Children and adults 10 years or older: IM or IV benzylpenicillin 1.2g -
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 12
Incorrect
-
The QRS duration of a broad-complex tachyarrhythmia is:
Your Answer:
Correct Answer: Greater than or equal to 0.12 s
Explanation:It’s a broad-complex tachycardia if the QRS duration is 0.12 seconds or more. It’s a narrow-complex tachycardia if the QRS complex is shorter than 0.12 seconds. The QRS duration should be examined if the patient with tachyarrhythmia is stable.
-
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 13
Incorrect
-
Which of the following is NOT a common side effect of antihistamines:
Your Answer:
Correct Answer: Tremor
Explanation:Common side effects of antihistamines may include:
Anticholinergic effects (blurred vision, dry mouth, urinary retention)
Headache
Gastrointestinal disturbances
Psychomotor impairment (sedation, dizziness and loss of appetite)
These side effects are significantly reduced with second-generation agents. -
This question is part of the following fields:
- Pharmacology
- Respiratory
-
-
Question 14
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
-
-
Question 15
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
-
-
Question 16
Incorrect
-
A 20-year-old boy took almost 25 tablets of paracetamol almost 4 hours ago. The boy is healthy and has no known comorbid or drug history.
Out of the following metabolic pathways, which one is primarily responsible for the toxic effects of paracetamol?Your Answer:
Correct Answer: N-hydroxylation
Explanation:Paracetamol 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%)Cytochrome P450 enzymes catalyse the oxidation of acetaminophen to the reactive metabolite 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.
-
This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
-
-
Question 17
Incorrect
-
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.
-
This question is part of the following fields:
- Infections
- Microbiology
-
-
Question 18
Incorrect
-
Ipratropium bromide should be used with caution in patients with which of the following conditions:
Your Answer:
Correct Answer: Prostatic hyperplasia
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
-
-
Question 19
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
-
-
Question 20
Incorrect
-
Intravenous glucose solutions are typically used in the treatment of all of the following situations except:
Your Answer:
Correct Answer: Hypokalaemia
Explanation:In hypokalaemia, initial potassium replacement therapy should not involve glucose infusions, as glucose may cause a further decrease in the plasma-potassium concentration. Glucose infusions are used for the other indications like diabetic ketoacidosis, hypoglycaemia, routine fluid maintenance in patients who are nil by mouth (very important in children), and in hyperkalaemia.
-
This question is part of the following fields:
- Fluids And Electrolytes
- Pharmacology
-
-
Question 21
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
-
-
Question 22
Incorrect
-
Which of the following best describes the therapeutic effect of calcium gluconate when used in treatment for hyperkalaemia:
Your Answer:
Correct Answer: Reduces cardiac cell membrane excitability
Explanation:Calcium resonium is an ion-exchange resin that exchanges sodium for potassium as it passes through the intestine, leading to excretion of potassium from the body. Salbutamol and insulin act to increase intracellular uptake of K+ via Na-K ATP pump. Sodium bicarbonate acts to correct acidosis and thus promotes intracellular uptake of K+. Calcium gluconate acts to protect the cardiac membrane and has no effect on serum K+ levels.
-
This question is part of the following fields:
- Fluids And Electrolytes
- Pharmacology
-
-
Question 23
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
-
-
Question 24
Incorrect
-
A 55-year-old male diabetic patient presents to the Emergency Room complaining of severe chest pain. His medical record shows that he had coronary angioplasty one week ago, during which he was administered abciximab.
Which of the following haematological diseases has a similar mechanism of action to this drug?Your Answer:
Correct Answer: Glanzmann’s thrombasthenia
Explanation:Abciximab is glycoprotein IIb/IIIa receptor antagonist that decreases aggregation of platelets by prevent their cross-linking. In Glanzmann’s thrombasthenia there are low levels of these same receptors leading to decreased bridging of platelets as fibrinogen cannot attach. There is increased bleeding time both in this disease and when there is use of abciximab.
-
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 25
Incorrect
-
Which of these is NOT a lithium side effect:
Your Answer:
Correct Answer: Peptic ulcer disease
Explanation:Adverse Effects of lithium Include
Leucocytosis (most patients)
Polyuria/polydipsia (30-50%)
Dry mouth (20-50%)
Hand tremor (45% initially, 10% after 1 year of treatment)
Confusion (40%)
Decreased memory (40%)
Headache (40%)
Muscle weakness (30% initially, 1% after 1 year of treatment)
Electrocardiographic (ECG) changes (20-30%)
Nausea, vomiting, diarrhoea (10-30% initially, 1-10% after 1-2 years of treatment)
Hyperreflexia (15%)
Muscle twitch (15%)
Vertigo (15%)
Extrapyramidal symptoms, goitre (5%)
Hypothyroidism (1-4%)
Acne (1%)
Hair thinning (1%) -
This question is part of the following fields:
- Central Nervous System
- Pharmacology
-
-
Question 26
Incorrect
-
A young farmer who is caught under farm machinery and suffering from a major crush injury is taken to the emergency department and requires a quick induction sequence. In this type of injury, which of the following anaesthetic medicines should be avoided?
Your Answer:
Correct Answer: Suxamethonium
Explanation:Suxamethonium is a neuromuscular blocker. It is contraindicated in patients who have experienced massive trauma, hyperkalemic, or burn injuries.
-
This question is part of the following fields:
- Anaesthesia
- Pharmacology
-
-
Question 27
Incorrect
-
A critically ill 48-year-old individual appears with symptoms and signs of an anaphylactic reaction.
In an allergic reaction, which of the following is an absolute contraindication to the injection of adrenaline?Your Answer:
Correct Answer: None of the other options
Explanation:Even if the following relevant contraindications exist, adrenaline can be given in life-threatening anaphylactic reactions:
Coronary artery disease (CAD)
Coronary artery disease (CAD) Second stage of labour
Hypertension that is uncontrolled
Severe Ventricular arrhythmias -
This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
-
-
Question 28
Incorrect
-
A 47-year-old woman comes in with palpitations that have been bothering her for the past four days. Her haemodynamics are normal, but her heart rate is currently 150 beats per minute. An ECG is performed, which reveals that she is experiencing atrial flutter. The patient is examined by a cardiology registrar, who recommends starting her on verapamil to control her ventricular rate while she waits for cardioversion.
In these circumstances, which of the following is a contraindication to the use of verapamil?Your Answer:
Correct Answer: Acute porphyria
Explanation:In most cases of atrial flutter, ventricular rate control is used as a stopgap measure until sinus rhythm is restored. A beta-blocker (e.g. bisoprolol), diltiazem, or verapamil can be used to reduce the rate of contractions in the heart.
Electrical cardioversion, pharmacological cardioversion, and catheter ablation can all be used to return the heart to a normal rhythm. Cardioversion should not be attempted until the patient has been fully anticoagulated for at least three weeks if the duration of atrial flutter is unknown or it has lasted longer than 48 hours. Emergency electrical cardioversion is the treatment of choice when there is a sudden onset of symptoms and haemodynamic compromise. For recurrent atrial flutter, catheter ablation is preferred.Verapamil is a calcium-channel blocker that is non-dihydropyridine phenylalkylamine and can be used to treat supraventricular arrhythmias. It’s a calcium channel blocker with a high negative inotropic effect that lowers cardiac output, slows the heart rate, and may impair atrioventricular conduction. At high doses, it can cause heart failure, exacerbate conduction disorders, and cause hypotension.
Adults should take 240-480 mg of verapamil in 2-3 divided doses. 5-10 mg IV over 30 seconds is the corresponding intravenous (IV) dose. After an IV injection, the peak effect lasts 3-5 minutes, and the action lasts 10-20 minutes.
Verapamil should not be taken with beta-blockers like atenolol or quinidine because the combination of their negatively inotropic and negatively chronotropic effects can result in severe hypotension, bradycardia, impaired atrioventricular conduction, heart failure (due to impaired cardiac contractility), and sinus arrest.
The use of verapamil is contraindicated in the following situations:
Acute porphyrias are a type of porphyria that occurs suddenly.
Accessory conducting pathways are linked to atrial flutter or fibrillation (e.g. Wolff-Parkinson-White-syndrome)
Bradycardia
Shock caused by the heart
Insufficiency of the heart (with reduced ejection fraction)
Left ventricular function has been significantly harmed in the past (even if controlled by therapy)
Hypotension (blood pressure less than 90 mmHg)
AV block in the second and third degrees
Sinusitis is a condition in which the sinuses become
Sino-atrial occlusion -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 29
Incorrect
-
Naloxone is a reversal agent for which of the following groups of drugs:
Your Answer:
Correct Answer: Opioids
Explanation:Naloxone is a specific antagonist of mu(μ)-opioid receptors, the specific antidote for opioid overdose and will reverse respiratory depression and coma if given at sufficient dosage. The initial dose is usually 0.8 mg (2 mL) intravenously (the dose range suggested by BNF is 0.4-2 mg). It can also be given by intramuscular injection if the intravenous route is not feasible.
As naloxone has a shorter duration of action than most opioids, close monitoring and repeated injections are necessary according to the respiratory rate and depth of coma. The dose is generally repeated every 2-3 minutes to a maximum of 10 mg. When repeated doses are needed, naloxone may be given by a continuous infusion adjusted according to the vital signs. Initially, the infusion rate can be set at 60% of the initial resuscitative IV dose per hour.
In opioid addicts, naloxone administration may precipitate a withdrawal syndrome with abdominal cramps, nausea and diarrhoea, but these usually settle within 2 hours. -
This question is part of the following fields:
- Anaesthesia
- Pharmacology
-
-
Question 30
Incorrect
-
What is the main mechanism of action of dopamine as an inotropic sympathomimetic:
Your Answer:
Correct Answer: Beta1-receptor agonist
Explanation:Dopamine is a neurotransmitter and a metabolic precursor of the catecholamines. It acts on beta1-receptors in cardiac muscle increasing cardiac contractility, and increases renal perfusion by stimulating dopamine receptors in the renal vasculature. This is of benefit in cardiogenic shock where deterioration of renal function is common.
-
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 31
Incorrect
-
You examine a 72-year-old man who has recently begun bumetanide treatment for worsening heart failure.
Which of these statements about bumetanide is correct?Your Answer:
Correct Answer: It has better intestinal absorption than furosemide
Explanation:Bumetanide is a loop diuretic that is used to treat congestive heart failure. It is frequently used in patients who have failed to respond to high doses of furosemide.
It has a potency of about 40 times that of furosemide, with a 1 mg dose being roughly equivalent to a 40 mg dose of furosemide.
Seizures are not known to be triggered by bumetanide. In fact, it lowers the concentration of neuronal chloride, making GABA’s action more depolarizing, and it’s currently being tested as an antiepileptic in the neonatal period.It takes effect after 1 hour of oral administration, and diuresis takes 6 hours to complete.
Bumetanide absorbs much better in the intestine than furosemide. Because it has a higher bioavailability than furosemide, it is commonly used in patients with gut oedema.
-
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 32
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.
-
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 33
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
-
-
Question 34
Incorrect
-
Salbutamol should be used with caution in patients with which of the following:
Your Answer:
Correct Answer: Susceptibility to QT-interval prolongation
Explanation:Beta-2 agonists should be used with caution in people with:
Cardiovascular disease, including arrhythmias and hypertension (beta-2 agonists may cause an increased risk of arrhythmias and significant changes to blood pressure and heart rate)
Diabetes(risk of hyperglycaemia and ketoacidosis, especially with intravenous use)
Hyperthyroidism(beta-2 agonists may stimulate thyroid activity)
Hypokalaemia(potentially serious hypokalaemia may result from beta-2 agonist therapy; this effect may be potentiated in severe asthma by concomitant treatment with theophylline, corticosteroids, diuretics and by hypoxia)
Susceptibility to QT-interval prolongation
Convulsive disorders -
This question is part of the following fields:
- Pharmacology
- Respiratory
-
-
Question 35
Incorrect
-
Calcium-channel blockers can be divided into two categories: dihydropyridines and non-dihydropyridines. The basic chemical structure of these two classes differs, as does their relative selectivity for cardiac versus vascular L-type calcium channels. The phenylalkylamine class and the benzothiazepine class are two subgroups of non-dihydropyridines.
A phenylalkylamine calcium-channel blocker is, for example, which of the following?Your Answer:
Correct Answer: Verapamil
Explanation:Calcium-channel blockers, also known as calcium antagonists, stop calcium from entering cells through the L-type calcium channel. This causes vascular smooth muscle in vessel walls to relax, resulting in a decrease in peripheral vascular resistance.
They can be used for a variety of things, including:
Hypertension
Angina
Atrial fibrillation
MigraineCalcium-channel blockers can be divided into two categories: dihydropyridines and non-dihydropyridines. The basic chemical structure of these two classes differs, as does their relative selectivity for cardiac versus vascular L-type calcium channels.
Dihydropyridines have a high vascular selectivity and lower systemic vascular resistance and blood pressure. As a result, they’re frequently used to treat hypertension. Modified release formulations are also used to treat angina, but their powerful systemic vasodilator and pressure-lowering effects can cause reflex cardiac stimulation, resulting in increased inotropy and tachycardia, which can counteract the beneficial effects of reduced afterload on myocardial oxygen demand.
The suffix -dpine distinguishes dihydropyridines from other pyridines. Examples of dihydropyridines that are commonly prescribed include:
Amlodipine
Felodipine
Nifedipine
NimodipineThe phenylalkylamine class and the benzothiazepine class are two subgroups of non-dihydropyridines.
Phenylalkylamines are less effective as systemic vasodilators because they are relatively selective for the myocardium. This group of drugs lowers myocardial oxygen demand and reverses coronary vasospasm, making them useful in the treatment of angina. They are also occasionally used to treat arrhythmias. A phenylalkylamine calcium-channel blocker like verapamil is an example.
In terms of selectivity for vascular calcium channels, benzothiazepines fall somewhere between dihydropyridines and phenylalkylamines. They can lower arterial pressure without producing the same level of reflex cardiac stimulation as dihydropyridines because they have both cardiac depressant and vasodilator effects. Diltiazem is the only benzothiazepine currently in clinical use.
-
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 36
Incorrect
-
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.
-
This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
-
-
Question 37
Incorrect
-
A young female was diagnosed with a urinary tract infection and was sent home with medications. However, after 48 hours of discharge, she returned to the hospital because there had been no relief from her symptoms. The urine sensitivity test report is still unavailable. Fresh blood tests were sent, and her estimated GFR is calculated to be >60 ml/minute.
She was prescribed nitrofurantoin 100 mg modified-release orally twice a day for two days.
Out of the following, which antibiotic is most appropriate to be prescribed to this patient?Your Answer:
Correct Answer: Fosfomycin
Explanation:The NICE guidelines for women with lower UTIs who are not pregnant are:
1. Consider prescribing a different antibiotic if symptoms do not improve within 48 hours or worsen at any time
2. If the urine culture and susceptibility test results are available, review the choice of antibiotic according to the results and change the antibiotic accordingly if symptoms are not improving or bacteria is resistant to the prescribed antibioticThe first choice of antibiotics for non-pregnant women aged 16 years and over is:
1. Nitrofurantoin
100 mg modified-release PO BD for 3 days – if eGFR >45 ml/minute
2. Trimethoprim
200 mg PO BD for three daysThe second-choice (no improvement in lower UTI symptoms on first-choice for at least 48 hours, or when first-choice is not suitable) are:
1. Nitrofurantoin
100 mg modified-release PO BD for three days – if eGFR >45 ml/minute
2. Pivmecillinam
400 mg PO initial dose, then 200 mg PO TDS for three days
3. Fosfomycin 3 g single sachet dose -
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 38
Incorrect
-
Which of the following is NOT a common side effect of adenosine:
Your Answer:
Correct Answer: Yellow vision
Explanation:Common side effects of adenosine include:
Apprehension
Dizziness, flushing, headache, nausea, dyspnoea
Angina (discontinue)
AV block, sinus pause and arrhythmia (discontinue if asystole or severe bradycardia occur) -
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 39
Incorrect
-
A 43 year old lady who has a previous medical history of hyperthyroidism presents to the emergency room with sweating, palpitations and agitation. On examination, she is tachycardic, hypertensive and hyperpyrexic. She recently had a stomach bug and has not been able to take her medication regularly. The best medication to immediately treat her symptoms is which of the following?
Your Answer:
Correct Answer: Propranolol
Explanation:There is a high suspicion of a thyroid crisis in this patient and emergent treatment should be initiated even before the results of TFT’s have returned. Antiadrenergic drugs like IV propranolol should be administered immediately to minimise sympathomimetic symptoms. Antithyroid medications like propylthiouracil or carbimazole should be administered to block further synthesis of thyroid hormones. After thionamide therapy has been started to prevent stimulation of new hormone synthesis, there should then be delayed administration of oral iodine solution. Hydrocortisone administration is also recommended as it treats possible relative adrenal insufficiency while also decreases peripheral conversion of T4 to T3.
-
This question is part of the following fields:
- Endocrine
- Pharmacology
-
-
Question 40
Incorrect
-
In patients requiring oxygen, who are at risk of hypercapnic respiratory failure, oxygen saturations should be maintained at:
Your Answer:
Correct Answer: 88 - 92%
Explanation:A lower target of 88 – 92% oxygen saturation is indicated for patients at risk of hypercapnic respiratory failure e.g. patients with COPD. Until blood gases can be measured, initial oxygen should be given using a controlled concentration of 28% or less, titrated towards the SpO2 of 88 – 92%. The aim is to provide the patient with enough oxygen to achieve an acceptable arterial oxygen tension without worsening carbon dioxide retention and respiratory acidosis.
-
This question is part of the following fields:
- Pharmacology
- Respiratory
-
-
Question 41
Incorrect
-
Which of the following presentations is NOT consistent with the diagnosis of anaphylaxis following exposure to a known allergen:
Your Answer:
Correct Answer: Generalised urticaria and angioedema alone
Explanation:Anaphylaxis is characterised by sudden onset and rapidly developing, life-threatening airway, breathing and circulation problems associated with skin and/or mucosal changes. Reactions can vary greatly, from hypotension alone, to reactions with predominantly asthmatic features, to cardiac/respiratory arrest. Skin or mucosal changes may be absent or subtle in up to 20% of cases but skin or mucosal changes alone are not a sign of an anaphylactic reaction.
-
This question is part of the following fields:
- Pharmacology
- Respiratory
-
-
Question 42
Incorrect
-
A 20-year-old asthmatic patient's symptoms is deteriorating and patient is moved to the resuscitation area of the Emergency Department. A loading dose of IV aminophylline is administered and her symptoms begin to improve. You are asked to check her theophylline levels after an appropriate time period.
How long should you wait before taking her blood sample be taken?
Your Answer:
Correct Answer: 4-6 hours
Explanation:Plasma theophylline concentration is usually measured five days after starting oral treatment and three days after each dose adjustment.
A blood sample to check theophylline concentration should usually be taken after 4-6 hours if an IV dose of aminophylline was given.
-
This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
-
-
Question 43
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
-
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 44
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.
-
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 45
Incorrect
-
Which of the following is NOT a typical feature of lithium toxicity:
Your Answer:
Correct Answer: Miosis
Explanation:Features of toxicity include:
Increasing gastrointestinal disturbances (vomiting, diarrhoea, anorexia)
Visual disturbances
Polyuria and incontinence
Muscle weakness and tremor
Tinnitus
CNS disturbances (dizziness, confusion and drowsiness increasing to lack of coordination, restlessness, stupor)
Abnormal reflexes and myoclonus
Hypernatraemia
With severe overdosage (serum-lithium concentration > 2 mmol/L) seizures, cardiac arrhythmias (including sinoatrial block, bradycardia and first-degree heart block), blood pressure changes, electrolyte imbalance, circulatory failure, renal failure, coma and sudden death may occur. -
This question is part of the following fields:
- Central Nervous System
- Pharmacology
-
-
Question 46
Incorrect
-
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.
-
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 47
Incorrect
-
You need to give your patient antibiotics, so you call microbiology for some advice.
Of the following antibacterial drugs, which of them is a protein synthesis inhibitor?
Your Answer:
Correct Answer: Erythromycin
Explanation:Bacteriostatic antibiotics include erythromycin and other macrolides. They work by attaching to the bacterial ribosome’s 50S subunit, preventing translocation and, as a result, inhibit protein synthesis. Macrolide antibiotics are actively concentrated inside leukocytes and delivered into the infection site as a result.
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
-
-
Question 48
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.
-
This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
-
-
Question 49
Incorrect
-
You are going to prescribe a NSAID to a 50-year-old male patient for his back pain. Which of the following NSAIDs is least likely to cause gastrointestinal side effects:
Your Answer:
Correct Answer: Ibuprofen
Explanation:NSAIDs are associated with serious gastrointestinal irritation and drug-induced ulcers.
Among the NSAIDs included in the choices, ibuprofen has the lowest risk.
Piroxicam, ketoprofen, and ketorolac trometamol are associated with the highest risk of serious upper gastrointestinal side effects.
Indomethacin, diclofenac, and naproxen are associated with an intermediate risk of serious upper gastrointestinal side effects.
-
This question is part of the following fields:
- Musculoskeletal
- Pharmacology
-
-
Question 50
Incorrect
-
What is the main mechanism of action of cyclizine:
Your Answer:
Correct Answer: Histamine-H1 antagonist
Explanation:Antihistamines e.g. cyclizine, are effective against nausea and vomiting caused by many different conditions, including motion sickness and vertigo. These agents act by inhibiting histamine pathways, and cholinergic pathways involved in transmission from the vestibular apparatus to the vomiting centre. There is no evidence that any one antihistamine is superior to another but their duration of action and incidence of adverse effects differ. Adverse effects include drowsiness and antimuscarinic effects such as blurred vision, dry mouth, urinary retention, constipation and confusion.
-
This question is part of the following fields:
- Central Nervous System
- Pharmacology
-
-
Question 51
Incorrect
-
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
-
-
Question 52
Incorrect
-
Which of the following states that the total pressure exerted by a mixture of gases is equal to the sum of the partial pressures of each of the gases in the mixture:
Your Answer:
Correct Answer: Dalton's law
Explanation:Dalton’s law states that when two or more gases, which do not react chemically, are present in the same container, the total pressure is the sum of the partial pressures of each gas.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 53
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.
-
This question is part of the following fields:
- Gastrointestinal
- Pharmacology
-
-
Question 54
Incorrect
-
Digoxin is contraindicated in all of the following EXCEPT for:
Your Answer:
Correct Answer: Asthma
Explanation:Digoxin is contraindicated in:Supraventricular arrhythmias associated with accessory conduction pathways e.g. Wolff-Parkinson-White syndromeVentricular tachycardia or fibrillationHeart conduction problems e.g. second degree or intermittent complete heart blockHypertrophic cardiomyopathy (unless concomitant atrial fibrillation and heart failure but should be used with caution)
-
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 55
Incorrect
-
A 35-year-old woman has complaints of nausea, abdominal pain and dark urine. On examination, you notice she has jaundice. She tells you she recently started a new medication.
Which drug is NOT likely to cause cholestatic jaundice out of the following?Your Answer:
Correct Answer: Isoniazid
Explanation:Isoniazid is an antibiotic used in the treatment of tuberculosis. It can cause acute, dose-dependent, hepatitis but is not a recognised cause of cholestatic jaundice.
The drugs that cause cholestatic jaundice are the following:
1. Nitrofurantoin
2. Erythromycin
3. Cephalosporins
4. Verapamil
5. NSAIDs
6. ACE inhibitors
7. Tricyclic antidepressants
8. Phenytoin
9. Azathioprine
10. Carbamazepine
11. Oral contraceptive pills
12. Diazepam
13. Ketoconazole
14. Tamoxifen -
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 56
Incorrect
-
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:
Correct 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
-
-
Question 57
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.
-
This question is part of the following fields:
- Musculoskeletal
- Pharmacology
-
-
Question 58
Incorrect
-
A patient who was put on low molecular weight heparin for suspected DVT and was scheduled for an ultrasound after the weekend, arrives at the emergency department with significant hematemesis. Which of the following medications can be used as a heparin reversal agent:
Your Answer:
Correct Answer: Protamine sulfate
Explanation:The management of bleeding in a patient receiving heparin depends upon the location and severity of bleeding, the underlying thromboembolic risk, and the current aPTT (for heparin) or anti-factor Xa activity (for LMW heparin). As an example, a patient with minor skin bleeding in the setting of a mechanical heart valve (high thromboembolic risk) and a therapeutic aPTT may continue heparin therapy, whereas a patient with major intracerebral bleeding in the setting of venous thromboembolism several months prior who is receiving heparin bridging perioperatively may require immediate heparin discontinuation and reversal with protamine sulphate. If haemorrhage occurs it is usually sufficient to withdraw unfractionated or low molecular weight heparin, but if rapid reversal of the effects of the heparin is required, protamine sulphate is a specific antidote (but only partially reverses the effects of low molecular weight heparins). Clinician judgment and early involvement of the appropriate consulting specialists is advised.
-
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 59
Incorrect
-
The risk of renal impairment in a patient on ACE inhibitor therapy is increased by concomitant treatment with which of the following drug classes:
Your Answer:
Correct Answer: NSAIDs
Explanation:Concomitant treatment with NSAIDs increases the risk of renal damage, and with potassium-sparing diuretics (or potassium-containing salt substitutes) increases the risk of hyperkalaemia. Hyperkalaemia and other side effects of ACE inhibitors are more common in the elderly and in those with impaired renal function and the dose may need to be reduced.
-
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 60
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.
-
This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
-
-
Question 61
Incorrect
-
Which of the following drugs used in the management of hyperkalaemia does not affect serum potassium levels:
Your Answer:
Correct Answer: Calcium gluconate
Explanation:Calcium gluconate is given to antagonise cardiac cell membrane excitability to reduce the risk of arrhythmias. It has no effect on serum potassium levels unlike the alternative drugs listed above.
-
This question is part of the following fields:
- Fluids And Electrolytes
- Pharmacology
-
-
Question 62
Incorrect
-
Which of the following best describes digoxin:
Your Answer:
Correct Answer: A positive inotrope and negative chronotrope
Explanation:Digoxin is a cardiac glycoside used in the treatment of atrial fibrillation and flutter, and congestive cardiac failure. It acts by inhibiting the membrane Na/K ATPase in cardiac myocytes. This raises intracellular sodium concentration and increases intracellular calcium availability indirectly via Na/Ca exchange. The increase in intracellular calcium levels causes an increases the force of myocardial contraction (positive inotrope), and slows the heart rate (negative chronotrope).
-
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 63
Incorrect
-
Nifedipine commonly causes which of the following adverse effects?
Your Answer:
Correct Answer: Ankle oedema
Explanation:Most common adverse effects of Nifedipine include:
Peripheral oedema (10-30%)
Dizziness (23-27%)
Flushing (23-27%)
Headache (10-23%)
Heartburn (11%)
Nausea (11%) -
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 64
Incorrect
-
Which of the following is NOT a typical electrolyte disturbance caused by furosemide:
Your Answer:
Correct Answer: Hypercalcaemia
Explanation:Adverse effects of loop diuretics include:
Mild gastrointestinal disturbances, pancreatitis and hepatic encephalopathy
Hyperglycaemia
Acute urinary retention
Water and electrolyte imbalance
Hyponatraemia, hypocalcaemia, hypokalaemia, hypomagnesaemia, hypochloraemiaHypotension, hypovolaemia, dehydration, and venous thromboembolism
Metabolic alkalosis
Hyperuricaemia
Blood disorders (bone marrow suppression, thrombocytopenia, and leucopenia)
Visual disturbance, tinnitus and deafness
Hypersensitivity reactions -
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 65
Incorrect
-
In adult advanced life support, which of the following best describes the correct administration of adrenaline for a non-shockable rhythm:
Your Answer:
Correct Answer: Give 1 mg of adrenaline as soon as intravenous access is achieved and every 3 - 5 minutes thereafter
Explanation:IV adrenaline 1 mg (10 mL of 1:10,000 solution) should be given after 3 shocks and every 3 – 5 minutes/after alternate shocks thereafter.
-
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 66
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
-
-
Question 67
Incorrect
-
Which of the following side effects is most likely caused by erythromycin:
Your Answer:
Correct Answer: QT - prolongation
Explanation:The side effects of erythromycin include abdominal pain, anaphylaxis,
cholestatic hepatitis, confusion,
diarrhoea, dyspepsia, fever, flatulence, hallucinations, hearing loss,
headache, hypertrophic pyloric stenosis, hypotension, Interstitial
nephritis, mild allergic reactions, nausea, nervous system effects,
including seizures, pain, pruritus, pseudomembranous colitis,
QT prolongation, rash, skin eruptions, tinnitus, urticaria,
ventricular arrhythmias, ventricular tachycardia, vertigo, vomiting -
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 68
Incorrect
-
A well recognised adverse effect of metoclopramide is which of the following?
Your Answer:
Correct Answer: Acute dystonic reaction
Explanation:Side effects of metoclopramide are commonly associated with extrapyramidal effects and hyperprolactinemia. Therefore its use must be limited to short-term use. Metoclopramide can induce acute dystonic reactions which involve facial and skeletal muscle spasms and oculogyric crises. These dystonic effects are more common in the young girls and young women, and in the very old. These symptoms usually occur shortly after starting treatment with this drug and subside within 24 hours of stopping it. Abortion of dystonic attacks can be carried out by injection of an antiparkinsonian drug like procyclidine.
-
This question is part of the following fields:
- Central Nervous System
- Pharmacology
-
-
Question 69
Incorrect
-
Which of the following best describes the mechanism of action of aspirin:
Your Answer:
Correct Answer: Cyclo-oxygenase (COX) inhibitor
Explanation:Aspirin is a non-steroidal anti-inflammatory drug (NSAID). Aspirin irreversibly inhibits cyclooxygenase (COX) enzymes and the resulting inhibition of prostaglandin synthesis results in analgesic, antipyretic and to a lesser extent anti-inflammatory actions.
-
This question is part of the following fields:
- Central Nervous System
- Pharmacology
-
-
Question 70
Incorrect
-
What is the main mechanism of action of metoclopramide:
Your Answer:
Correct Answer: Dopamine antagonist
Explanation:Metoclopramide is a dopamine-receptor antagonist. Blockade of inhibitory dopamine receptors in the GI tract may allow stimulatory actions of ACh at muscarinic synapses to predominate. Metoclopramide also blocks dopamine D2-receptors within the chemoreceptor trigger zone (CTZ). At high doses, it is also thought to have some 5-HT3antagonist activity.
-
This question is part of the following fields:
- Central Nervous System
- Pharmacology
-
-
Question 71
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.
-
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 72
Incorrect
-
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:
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.
-
This question is part of the following fields:
- Gastrointestinal Pharmacology
- Pharmacology
-
-
Question 73
Incorrect
-
In the treatment of bradyarrhythmias with adverse characteristics or risk of asystole, what is the initial suggested dose of atropine?
Your Answer:
Correct Answer: 500 micrograms
Explanation:Atropine 500 mcg IV bolus should be administered if there are any adverse features or risk of asystole. If the reaction is not adequate, repeat the steps every 3 to 5 minutes up to a maximum dose of 3 mg. In the case of acute myocardial ischemia or myocardial infarction, atropine should be taken with caution since the increased heart rate may aggravate the ischemia or increase the size of the infarct.
-
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 74
Incorrect
-
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
-
-
Question 75
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
-
This question is part of the following fields:
- Anaesthesia
- Pharmacology
-
-
Question 76
Incorrect
-
The mechanism of action of abciximab is by:
Your Answer:
Correct Answer: Blocking the binding of fibrinogen to GPIIb/IIIa receptor sites
Explanation:Abciximab is a glycoprotein IIb/IIIa inhibitors and prevents platelet aggregation by blocking the binding of fibrinogen to receptors on platelets.
-
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 77
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.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 78
Incorrect
-
You investigated a patient with a chest infection and want to start antibiotics right away. The patient says they she can't take cephalosporins when you ask about allergies.
Choose the 'second-generation' cephalosporin from the following choices?Your Answer:
Correct Answer: Cefuroxime
Explanation:Cephalosporins of the first generation include cephalexin, cefradine, and cefadroxil. Urinary tract infections, respiratory tract infections, otitis media, and skin and soft-tissue infections are all treated with them.
Second-generation cephalosporins include cefuroxime, cefaclor, and cefoxitin. These cephalosporins are less vulnerable to beta-lactamase inactivation than the ‘first-generation’ cephalosporins. As a result, they’re effective against germs that are resistant to other antibiotics, and they’re especially effective against Haemophilus influenzae.
Cephalosporins of the third generation include cefotaxime, ceftazidime, and ceftriaxone. They are more effective against Gram-negative bacteria than second generation’ cephalosporins. They are, however, less effective against Gram-positive bacteria such Staphylococcus aureus than second-generation cephalosporins.
-
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 79
Incorrect
-
One of your patients is in resuscitation and is suffering from kidney failure. The intensive care outreach team arrives to assess them and determines that a dopamine infusion is necessary.
Dopamine primarily acts on which of the following receptors at low doses?Your Answer:
Correct Answer: Dopamine receptors
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.
Below is a summary of the mechanisms and effects of various inotropic agents:
Inotrope
Mechanism
Effects
Adrenaline (epinephrine)
Beta-1 and -2 agonist at increasing doses;
Alpha-agonist at high doses
Increased cardiac output;
Vasoconstriction at higher doses
Noradrenaline (norepinephrine)
Mainly alpha-agonist;
Beta-1 and -2 agonist at increasing doses
Vasoconstriction;
Some increased cardiac output
Dopamine
Dopamine agonist at low doses;
Beta-1 and -2 agonist at increasing doses;
Alpha-agonist at high doses
Increased cardiac output;
Vasoconstriction at higher doses
Dobutamine
Mainly beta-1 agonist
Increased cardiac output -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 80
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
-
-
Question 81
Incorrect
-
In patients who are not at risk of hypercapnic respiratory failure but are requiring oxygen, the oxygen saturations should be maintained at which of the following?
Your Answer:
Correct Answer: 94 - 98%
Explanation:Oxygen saturation should be 94 – 98% in most acutely ill patients with a normal or low arterial carbon dioxide (PaCO2). In some clinical situations, however, like cardiac arrest and carbon monoxide poisoning, it is more appropriate to aim for the highest possible oxygen saturation until the patient is stable.
-
This question is part of the following fields:
- Pharmacology
- Respiratory
-
-
Question 82
Incorrect
-
In adult basic life support, chest compressions should be performed at which of the following rates:
Your Answer:
Correct Answer: 100 - 120 per minute
Explanation:Chest compressions should be performed at a rate of 100 – 120 per minute.
-
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 83
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
-
-
Question 84
Incorrect
-
A 67-year-old woman complains of general malaise, nausea, and vomiting. She is perplexed and declares that everything 'looks yellow.' Her potassium level is 6.8 mmol/l, according to a blood test.
Which of the drugs listed below is most likely to be the cause of her symptoms?Your Answer:
Correct Answer: Digoxin
Explanation:Because digoxin has a narrow therapeutic index, it can cause toxicity both during long-term therapy and after an overdose. Even when the serum digoxin concentration is within the therapeutic range, it can happen.
Acute digoxin toxicity usually manifests itself within 2-4 hours of an overdose, with serum levels peaking around 6 hours after ingestion and life-threatening cardiovascular complications following 8-12 hours.
Chronic digoxin toxicity is most common in the elderly or those with impaired renal function, and it is often caused by a coexisting illness. The clinical signs and symptoms usually appear gradually over days to weeks.
The following are characteristics of digoxin toxicity:
Nausea and vomiting
Diarrhoea
Abdominal pain
Confusion
Tachyarrhythmias or bradyarrhythmias
Xanthopsia (yellow-green vision)
Hyperkalaemia (early sign of significant toxicity)Some precipitating factors are as follows:
Elderly patients
Renal failure
Myocardial ischaemia
Hypokalaemia
Hypomagnesaemia
Hypercalcaemia
Hypernatraemia
Acidosis
Hypothyroidism
Spironolactone
Amiodarone
Quinidine
Verapamil
Diltiazem -
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 85
Incorrect
-
After what time period should intravenous phenytoin be used as second-line treatment of status epilepticus?
Your Answer:
Correct Answer: 25 minutes
Explanation:If seizures recur or fail to respond after initial treatment with benzodiazepines within 25 minutes of onset, phenytoin sodium, fosphenytoin sodium, or phenobarbital sodium should be used.
-
This question is part of the following fields:
- Central Nervous System
- Pharmacology
-
-
Question 86
Incorrect
-
A 68-year-old man has a very fast heartbeat' and is out of breath. He has had a heart transplant in the past. His electrocardiogram reveals supraventricular tachycardia.
Which of the following is the most appropriate adenosine dose for him to receive as a first dose?Your Answer:
Correct Answer: Adenosine 3 mg IV
Explanation:A rapid IV bolus of adenosine is given, followed by a saline flush. The standard adult dose is 6 mg, followed by 12 mg if necessary, and then another 12 mg bolus every 1-2 minutes until an effect is seen.
Patients who have had a heart transplant, on the other hand, 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.
-
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 87
Incorrect
-
Which of the following corticosteroids has the most potent mineralocorticoid effect:
Your Answer:
Correct Answer: Fludrocortisone
Explanation:Fludrocortisone has the most potent mineralocorticosteroid activity, making it ideal for mineralocorticoid replacement in adrenal insufficiency.
-
This question is part of the following fields:
- Endocrine
- Pharmacology
-
-
Question 88
Incorrect
-
Which of the following statements is correct regarding the partial pressure of oxygen during respiration?
Your Answer:
Correct Answer: Exhaled PO 2 > Alveolar PO 2
Explanation:Because of humidification, inspired PO2 in the airways is less than inhaled PO2.
Because of gas exchange, alveolar PO2 is less than inhaled or inspired PO2.
Because of mixing with anatomical dead space (air that has not taken part in gas exchange, exhaled PO2 is greater than alveolar O2, and therefore that has relatively higher PO2 on the way out, but is less than inhaled or inspired PO2.
Typical values for a resting young healthy male (in kPa) are shown below:
-Inhaled air: PO221.2, PCO20.0
-Inspired air in airways (after humidification): PO219.9, PCO20.0
-Alveolar air (after equilibrium with pulmonary capillaries): PO213.3, PCO25.3
-Exhaled air (after mixing with anatomical dead space air): PO215.5, PCO24.3 -
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 89
Incorrect
-
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.
-
This question is part of the following fields:
- Endocrine
- Pharmacology
-
-
Question 90
Incorrect
-
Regarding co-amoxiclav, which of the following statements is INCORRECT:
Your Answer:
Correct Answer: Clavulanic acid acts to inhibit cross-linking of bacterial peptidoglycan polymers.
Explanation:Co-amoxiclav consists of amoxicillin with the beta-lactamase inhibitor clavulanic acid. Clavulanic acid itself has no significant antibacterial activity but, by inactivating beta-lactamases, it makes the combination active against beta-lactamase-producing bacteria that are resistant to amoxicillin.The most common adverse effects of co-amoxiclav include nausea, vomiting, skin rash and diarrhoea. Pseudomembranous colitis should be considered if a person develops severe diarrhoea during or after treatment with co-amoxiclav. Cholestatic jaundice can occur either during or shortly after the use of co-amoxiclav. An epidemiological study has shown that the risk of acute liver toxicity was about 6 times greater with co-amoxiclav than with amoxicillin. Cholestatic jaundice is more common in patients above the age of 65 years and in men; these reactions have only rarely been reported in children. Jaundice is usually self-limiting and very rarely fatal.
-
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 91
Incorrect
-
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:
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
-
-
Question 92
Incorrect
-
A 40-year-old man who has a history of asthma arrives at the emergency department complaining of palpitations that have been going on for 5 days. Which of the following beta-blockers is the safest for an asthmatic patient?
Your Answer:
Correct Answer: Atenolol
Explanation:Atenolol is a beta blocker, which is a type of medication that works by preventing certain natural substances in the body, such as epinephrine, from acting on the heart and blood vessels.
This effect reduces heart rate, blood pressure, and cardiac strain. Atenolol, bisoprolol fumarate, metoprolol tartrate, nebivolol, and (to a lesser extent) acebutolol have a lower action on beta2 (bronchial) receptors and are thus cardio selective but not cardiac specific.
They have a lower effect on airway resistance, although they are not without this adverse effect.
-
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 93
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.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 94
Incorrect
-
An 82 year old man taking warfarin as a maintenance medication comes in to your clinic because of an infection. Which antibiotic is the safest choice for this patient?
Your Answer:
Correct Answer: Cefalexin
Explanation:Alterations in the international normalized ratio (INR) brought about by the concurrent use of antibiotics and warfarin may result in either excessive clotting or excessive bleeding if they are deemed to have a high risk for interaction. As such, there should be careful consideration of the class of antibiotic to be used.
Antibiotics from the following drug classes should generally be avoided as they have a high risk for interaction with warfarin, possible enhancing the anticoagulant effects of warfarin resulting in bleeding: Fluoroquinolones (e.g. ciprofloxacin, levofloxacin), Macrolides (e.g. clarithromycin, erythromycin, azithromycin), Nitroimidazoles (e.g. metronidazole), Sulphonamides (e.g. co-trimoxazole, a combination of trimethoprim and sulfamethoxazole), Trimethoprim, Tetracyclines (e.g. doxycycline).
Low risk antibiotics that have low risk for interaction with warfarin includes cephalexin, from the cephalosporin class, and clindamycin which is a lincomycin.
-
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 95
Incorrect
-
What is the recommended dosing regime for amiodarone in the treatment of a stable regular broad-complex tachycardia:
Your Answer:
Correct Answer: 300 mg IV over 10 - 60 minutes, followed by an IV infusion of 900 mg over the next 24 hours
Explanation:A ventricular tachycardia (or broad-complex tachycardia of uncertain origin) should be treated with amiodarone 300 mg IV over 10 – 60 min, followed by an infusion of 900 mg over the next 24 hours.
-
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 96
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.
-
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 97
Incorrect
-
An elderly patient presents to ED following a fall after feeling light headed when standing up. You are reviewing his medication and note that he is taking a high dose of furosemide. Loop diuretics act primarily at which of the following sites in the nephron:
Your Answer:
Correct Answer: Thick ascending limb
Explanation:Loop diuretics inhibit the Na+/K+/2Cl- symporter on the luminal membrane in the thick ascending limb of the loop of Henle, thus preventing reabsorption of NaCl and water. These agents reduce reabsorption of Cl- and Na+ and increase Ca2+ excretion and loss of K+ and Mg2+.
-
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 98
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.
-
This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
-
-
Question 99
Incorrect
-
Which of the following classes of drugs may predispose to lithium toxicity:
Your Answer:
Correct Answer: Thiazide diuretics
Explanation:Excretion of lithium may be reduced by thiazide diuretics, NSAIDs, and ACE inhibitors thus predisposing to lithium toxicity. Loop diuretics also cause lithium retention but are less likely to result in lithium toxicity.
-
This question is part of the following fields:
- Central Nervous System
- Pharmacology
-
-
Question 100
Incorrect
-
Which of the following conditions require IV Lidocaine administration?
Your Answer:
Correct Answer: Refractory ventricular fibrillation in cardiac arrest
Explanation:IV Lidocaine is indicated in Ventricular Arrhythmias or Pulseless Ventricular Tachycardia (after defibrillation, attempted CPR, and vasopressor administration)
-
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
SESSION STATS - PERFORMANCE PER SPECIALTY
