Antimicrobials USMLE Step 1 Practice Question
A 41-year-old man with severe acne is prescribed isotretinoin and concurrently takes doxycycline for secondary bacterial infection. He develops severe frontal headache, blurred vision, and diplopia. Vital signs show BP 128/82, HR 92, RR 16, temp 37.2°C, SpO2 98%. MRI demonstrates papilledema and enlarged blind spot on visual field testing. Fundoscopy reveals no focal neurologic deficits. Which of the following best explains this adverse effect?
Answer choices
- ADrug-induced vasculitis affecting cerebral vessels
- BHepatotoxicity impairing intracranial pressure regulation
- CAdditive intracranial hypertension from isotretinoin and doxycyclineCorrect answer
- DBacterial meningitis from doxycycline resistance selection
- ESynergistic teratogenicity from isotretinoin and tetracycline combination
- FVitamin A toxicity from isotretinoin accumulation impairing CSF absorption at arachnoid granulations
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