N Engl J Med

Odansetron for home use after emergency visits reduces pediatric gastroenteritis symptoms in children

July 21, 2025

Supplying caregivers with oral ondansetron for prn use was linked to lower rates of moderate-to-severe gastroenteritis signs/symptoms over the 7 days after pediatric emergency department discharge, in this double-blind RCT of children with acute gastroenteritis–associated vomiting.

Study details. This multi-site, double-blind, randomized superiority trial included 1,030 patients aged 6 months to under 18 years with acute gastroenteritis–related vomiting seen at six pediatric emergency departments. Caregivers were supplied with six doses of oral ondansetron vs. placebo for prn use in response to vomiting in the first 48 hours post-enrollment. Primary outcome: moderate-to-severe gastroenteritis scores (9+ out of 20 on the modified Vesikari scale) during the 7 days after study enrollment. Secondary outcomes: vomiting, number of vomiting episodes up to 48 hours after enrollment, duration from first to last vomiting episode after enrollment, unscheduled physician visits up to 7 days after enrollment, IV fluids use.

Results. Moderate-to-severe gastroenteritis was reported in 5.1% of children with ondansetron vs. 12.5% with placebo. After adjustments for trial site, patient weight, and missing data, ondansetron was linked to a lower risk of moderate-to-severe gastroenteritis vs. placebo (adjusted odds ratio, 0.50; 95% confidence interval [CI], 0.40-0.60). The number of vomiting episodes up to 48 hours post-enrollment was lower with ondansetron vs. placebo (adjusted rate ratio, 0.76; 95% CI, 0.67-0.87). However, no meaningful differences were noted regarding presence (or median duration) of vomiting, number of unscheduled physician visits, or IV fluid use. Adverse events weren’t meaningfully different between groups.

Source:

Freedman SB, et al; Pediatric Emergency Research Canada Innovative Clinical Trials Study Group. (2025, July 17). N Engl J Med. Multidose Ondansetron after Emergency Visits in Children with Gastroenteritis. https://pubmed.ncbi.nlm.nih.gov/40673584/