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

## TL;DR

This study finds that low-dose ondansetron slightly prolongs heart intervals in healthy children but does not cause dangerous heart rhythms.

## Contribution

The study is the first to systematically evaluate QTc interval changes in healthy pediatric patients receiving low-dose ondansetron.

## Key findings

- Low-dose ondansetron caused a small but significant increase in QTc and Tp-e intervals in healthy children.
- No cardiac dysrhythmias were observed despite QTc prolongation.
- The risk of significant QTc prolongation was low at 2.5%.

## Abstract

The aim of this study was to describe electrocardiographic changes in healthy pediatric patients receiving low-dose ondansetron and to determine whether these changes are associated with the occurrence of cardiac dysrhythmias.

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 corrected QT interval (QTc) interval. The mean variation of the Tp-e interval and the incidence of significant QTc prolongation were assessed as secondary outcomes.

Four studies were included in this review, including 231 healthy pediatric patients who received ondansetron (IV or oral). Most were male, aged 0.6–18 years. The mean IV ondansetron dose ranged from 0.1 to 0.2 mg/kg, while the mean oral dose was 0.18 mg/kg, with a maximum dose of 8 mg. The mean change in the QTc interval was 4.7 ms (95% confidence interval [CI] 1.48.1), and in the Tp-e interval was 7.7 ms (95%CI 2.0–13.5). The risk of a significant QTc prolongation was 2.5% (95%CI -0.009–0.059). No dysrhythmia was observed in the studies.

There was a statistically significant increase in QTc and Tp-e intervals following ondansetron administration in healthy pediatric patients. However, it is highly unlikely that these changes result in cardiac dysrhythmia, suggesting no relationship between low-dose ondansetron use and an increased risk of dysrhythmia in healthy pediatric patients.