Antiemetic choice in Parkinson's disease and prolonged QT — FRCA Primary MCQ

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HardPharmacologyAntiemetic choice in Parkinson's disease and prolonged QTFRCA Primary

A 52-year-old man with Parkinson's disease develops postoperative nausea after bowel surgery. He is taking levodopa and has a prolonged QTc of 490 ms. Which antiemetic is most appropriate?

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Correct answer: C — Haloperidol

Dexamethasone does not antagonise dopamine receptors and does not usually prolong QT to the same extent as 5-HT3 antagonists or butyrophenones. Metoclopramide, haloperidol and droperidol may worsen Parkinsonism through dopamine antagonism and can be problematic with QT prolongation. Ondansetron is effective but may further prolong QTc. The clinical pearl is that antiemetic choice should consider both receptor pharmacology and ECG risk.

Reference: RCoA Primary FRCA Syllabus 2026; Peck, Hill & Williams Pharmacology for Anaesthesia