Torsades de Pointes Following Ondansetron Administration: A Case Report with literature review
Introduction Ondansetron blocks human ether-à-go-go-related gene (hERG) potassium channels, causing QT prolongation and risk of torsades de pointes (TdP). Despite its widespread use, TdP following a standard intravenous dose is rarely reported. This report presents a case of a 40-year-old female who developed TdP…
2026 1,405 reads 0 citations
Case Reports
Torsades de Pointes Following Ondansetron Administration: A Case Report with literature review
IntroductionOndansetron blocks human ether-à-go-go-related gene (hERG) potassium channels, causing QT prolongation and risk of torsades de pointes (TdP). Despite its widespread use, TdP following a standard intravenous dose is rarely reported. This report presents a case of a 40-year-old female who developed TdP after receiving an 8 mg intravenous dose of ondansetron.
Case PresentationA 40-year-old female with no significant past medical history presented with vomiting and diarrhea. Approximately 30 minutes after receiving 8 mg of intravenous ondansetron, she developed TdP requiring cardioversion. Laboratory results revealed mild hypokalemia (3.12 mmol/L). Post-event troponin elevation and Grade I diastolic dysfunction suggested transient myocardial involvement. She was stabilized with potassium replacement and supportive care, with full recovery.
Literature ReviewFive cases of ondansetron-induced TdP were reviewed. Patient ages ranged from 41 to 60 years, one case (20%) involved oral administration and four cases (80%) involved intravenous administration. Doses ranged from standard 4 mg to cumulative 36 mg infusions, with QTc intervals reaching up to 653 ms. Presenting events included TdP, ventricular tachycardia, and cardiac arrest. Symptom resolution and recovery were achieved in all cases following medical intervention and electrolyte correction.
ConclusionThis case highlights that standard-dose ondansetron can precipitate TdP in physiologically unstable patients.
Keywords Ondansetron Torsades de pointes QT prolongation Hypokalemia Drug-induced arrhythmia All subjects
Barw Medical Journal. 2026;4(1):60–64