Oral ondansetron for gastroenteritis in a pediatric emergency department.

Vomiting limits the success of oral rehydration in children with gastroenteritis. We conducted a double-blind trial to determine whether a single oral dose of ondansetron, an antiemetic, would improve outcomes in children with gastroenteritis. We enrolled 215 children 6 months through 10 years of age who were treated in a pediatric emergency department for gastroenteritis and dehydration. After being randomly assigned to treatment with orally disintegrating ondansetron tablets or placebo, the children received oral-rehydration therapy according to a standardized protocol. The primary outcome was the proportion who vomited while receiving oral rehydration. The secondary outcomes were the number of episodes of vomiting and the proportions who were treated with intravenous rehydration or hospitalized. As compared with children who received placebo, children who received ondansetron were less likely to vomit (14 percent vs. 35 percent; relative risk, 0.40; 95 percent confidence interval, 0.26 to 0.61), vomited less often (mean number of episodes per child, 0.18 vs. 0.65; P<0.001), had greater oral intake (239 ml vs. 196 ml, P=0.001), and were less likely to be treated by intravenous rehydration (14 percent vs. 31 percent; relative risk, 0.46; 95 percent confidence interval, 0.26 to 0.79). Although the mean length of stay in the emergency department was reduced by 12 percent in the ondansetron group, as compared with the placebo group (P=0.02), the rates of hospitalization (4 percent and 5 percent, respectively; P=1.00) and of return visits to the emergency department (19 percent and 22 percent, P=0.73) did not differ significantly between groups. In children with gastroenteritis and dehydration, a single dose of oral ondansetron reduces vomiting and facilitates oral rehydration and may thus be well suited for use in the emergency department. Copyright 2006 Massachusetts Medical Society.