FCEM2-0583
A 45-year-old man presents to the Emergency Department anxious, confused, and agitated. He has also vomited several times. He has recently been prescribed a course of amoxicillin for a presumed sinus infection by his primary care physician. You are unable to obtain a coherent medical history from him, but he has his regular medications with him, which include: ibuprofen, atorvastatin, and metformin. He has a friend with him who states he stopped taking his medications a few days ago. His vital signs are: temperature 38.9°C, heart rate 138, respiratory rate 23, blood pressure 173/96, and oxygen saturation 97% on room air.
What is the SINGLE most likely diagnosis?