CNS Pharmacology USMLE Step 1 Practice Question
A 42-year-old woman with generalized anxiety disorder has been stable on sertraline 100 mg daily for 2 years. She presents to the emergency department 3 days after starting fluconazole 400 mg daily for vulvovaginal candidiasis. She reports tremor, agitation, and diarrhea that began the day after fluconazole initiation. On examination, temperature is 37.9°C, heart rate 112 bpm, blood pressure 140/85 mmHg. She has hyperreflexia, bilateral ankle clonus, and diaphoresis. Laboratory studies show sodium 127 mEq/L and creatinine 0.9 mg/dL. She denies fever, headache, or muscle rigidity. Which of the following best explains this clinical presentation?
Answer choices
- AFluconazole-induced inhibition of CYP3A4 causing increased sertraline metabolism and withdrawal syndrome
- BSerotonin syndrome resulting from fluconazole inhibition of CYP2D6, increasing sertraline levelsCorrect answer
- CDrug-induced hyponatremia from sertraline causing increased neuronal irritability
- DAcute angle-closure glaucoma precipitated by sympathomimetic effects of fluconazole
- EFluconazole-induced direct inhibition of monoamine oxidase leading to serotonergic excess
- FNeuroleptic malignant syndrome from fluconazole's dopamine antagonist properties
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