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Antipsychotic metabolic adverse effects — USMLE Step 3 MCQ

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HardPsychiatryAntipsychotic metabolic adverse effectsUSMLE Step 3

A 44-year-old woman develops diplopia, dysarthria, dry mouth, fixed dilated pupils, and symmetric descending weakness 18 hours after eating home-canned vegetables. Sensation and mental status are intact. Forced vital capacity is falling, and stool and serum toxin assays have been sent. Which action is most appropriate now?

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Correct answer: D — Consult public health and give heptavalent antitoxin before assay confirmation

The best answer is “Consult public health and give heptavalent antitoxin before assay confirmation”. The cranial neuropathies, autonomic findings, and symmetric descending paralysis after home-canned food are classic foodborne botulism. Antitoxin prevents circulating toxin from binding additional nerve terminals and must be given promptly through public-health coordination; laboratory confirmation takes time. Respiratory monitoring and intubation occur as needed. Standard immune globulin, pyridostigmine, and plasma exchange are not substitutes.

Reference: CDC Clinical Care of Botulism: https://www.cdc.gov/botulism/hcp/clinical-care/index.html