Review Question - QID 214953

A 27-year-old man presents to the emergency department with altered mental status. He has become gradually more confused over the past several days. His wife also notes he has had diarrhea, nausea and vomiting, and abdominal pain for the past week. The patient has a history of depression and multiple suicide attempts. He takes fluoxetine as well as over-the-counter pain medications for a recent muscle strain. He works in a large industrial compound that manufactures semiconductors. He exercises regularly and recently has started making his own beer at home. His temperature is 98.3°F (36.8°C), blood pressure is 107/75 mmHg, pulse is 110/min, respirations are 22/min, and oxygen saturation is 99% on room air. Physical exam reveals a confused man with a garlic odor on his breath and the finding in Figure A. Cardiopulmonary exam reveals a rapid heart rate with no murmurs and clear breath sounds. Which of the following is the most likely etiology of this patient's symptoms?