BOTTOM LINE: It is generally safe and effective to discharge vomiting pediatric patients with a prescription for ondansetron, and a recent study supported this common practice.
While it has become common practice to prescribe ondansetron to children with emesis, a 2025 randomized controlled study showed that a prescription for ondansetron decreased the risk of moderate to severe gastroenteritis in the following 7 days.
This study compared children 6 months to 18 years of age who received either ondansetron or placebo. They found a rates of moderate to severe gastroenteritis to be 5.1% in the ondansetron group versus 12.5% in the placebo group.
*Note that ondansetron is NOT approved for children under 6 months of age or in those with prolonged QT.
References
Freedman SB, Williamson-Urquhart S, Plint AC, Dixon A, Beer D, Joubert G, Pechlivanoglou P, Finkelstein Y, Heath A, Zhang JZ, Wallace A, Offringa M, Klassen TP; Pediatric Emergency Research Canada Innovative Clinical Trials Study Group. Multidose Ondansetron after Emergency Visits in Children with Gastroenteritis. N Engl J Med. 2025 Jul 17;393(3):255-266. doi: 10.1056/NEJMoa2503596. PMID: 40673584.
