Ondansetron Slightly Prolongs QTc Interval in Pediatrics Without Dysrhythmia Risk

OBJECTIVE: 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. DATA SOURCE: 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. DATA SYNTHESIS: 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. CONCLUSIONS: 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.