CNS Pharmacology USMLE Step 1 Practice Question
A 52-year-old man with treatment-resistant major depressive disorder has been taking phenelzine 45 mg daily for 8 months with adequate symptom control. His psychiatrist adds sertraline 50 mg daily, and 1 week later the patient presents to the emergency department with confusion, agitation, and severe muscle rigidity. Vital signs: BP 158/92 mmHg, HR 118 bpm, RR 22/min, T 38.9°C. On examination, he has spontaneous clonus, brisk reflexes, and is diaphoretic. Laboratory studies show creatine kinase 1200 U/L, sodium 138 mEq/L, and myoglobinuria. The patient denies recent fevers, sick contacts, or exposure to new medications other than sertraline. Which of the following is the most likely diagnosis?
Answer choices
- ASerotonin syndromeCorrect answer
- BNeuroleptic malignant syndrome
- CMalignant hyperthermia
- DAnticholinergic toxicity
- ESepsis with acute encephalitis
- FThyroid storm
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