Effect of ondansetron on QTc interval prolongation in healthy pediatric patients: a systematic review and meta-analysis.

Low-dose ondansetron produced a statistically significant mean increase in the corrected QT interval (QTc) of 4.7 ms in healthy pediatric patients.

• The mean change in the QTc interval was 4.7 ms (95% CI 1.4–8.1).
• Four studies encompassing 231 healthy pediatric patients were included in the meta-analysis.
• Patients received ondansetron either intravenously (IV) or orally; mean IV dose ranged from 0.1 to 0.2 mg/kg and mean oral dose was 0.18 mg/kg (maximum 8 mg).
• Patients were aged 0.6–18 years, with most being male.

Low-dose ondansetron produced a statistically significant mean increase in the Tp-e interval of 7.7 ms in healthy pediatric patients.

• The mean change in the Tp-e interval was 7.7 ms (95% CI 2.0–13.5).
• The Tp-e interval was assessed as a secondary outcome measure.
• This finding was based on the same four included studies with 231 patients.

The risk of clinically significant QTc prolongation following low-dose ondansetron in healthy pediatric patients was 2.5%.

• The risk of a significant QTc prolongation was 2.5% (95% CI -0.009–0.059).
• Incidence of significant QTc prolongation was assessed as a secondary outcome.
• The confidence interval crossed zero, indicating imprecision in the estimate.

No cardiac dysrhythmias were observed in any of the included studies following ondansetron administration.

• Zero dysrhythmia events were recorded across all four included studies.
• Despite statistically significant increases in QTc and Tp-e intervals, no ventricular arrhythmias occurred.
• The authors concluded it is 'highly unlikely that these changes result in cardiac dysrhythmia.'

The systematic review included four studies with 231 healthy pediatric patients receiving ondansetron as an antiemetic.

• The search was conducted in PubMed, EMBASE, LILACS, SciELO, and the Cochrane databases, selecting articles published until September 2024.
• The primary outcome was the mean change in the QTc interval.
• Patients were aged 0.6–18 years and most were male.
• Ondansetron was administered either intravenously or orally.