Major Adverse Cardiac Events with Ondansetron: A Systematic Review

Area of Science:

• Pharmacology
• Cardiology
• Clinical Pharmacy

Background:

• Ondansetron is flagged for QT interval prolongation, a known risk factor for cardiac events.
• Medication safety alerts frequently cite ondansetron due to this potential risk.
• Major adverse cardiac events (MACE) associated with QT prolongation include death, cardiac arrest, and arrhythmias.

Purpose of the Study:

• To systematically review and meta-analyze the literature on ondansetron's association with MACE.
• To evaluate the risk of QT-prolongation-related cardiac events in adult patients receiving ondansetron compared to placebo.

Main Methods:

• Searched Medline, Embase, International Pharmaceutical Abstracts, and Cochrane Central for relevant randomized controlled trials (RCTs).
• Included RCTs comparing ondansetron to placebo in adults, focusing on MACE outcomes.
• Performed random-effects meta-analyses, applying corrections for studies with zero events.

Main Results:

• Included 170 RCTs with 23,421 adult participants; 70% were surgical patients.
• A total of seven MACE (all deaths) were reported across all included trials.
• Ondansetron was not associated with an increased risk of mortality (RR: 1.03, 95% CI: 0.76-1.39) or arrhythmias.

Conclusions:

• The current literature does not support an association between ondansetron use and increased MACE or mortality.
• The low number of reported cardiac events limited the ability to perform definitive meta-analyses.
• Further research is warranted to refine understanding of QT-prolonging medications and optimize medication safety alerts.