What is the comparative clinical effectiveness of ondansetron alone or in combination with oral rehydration therapy versus oral rehydration therapy alone for pediatric patients with or at risk of mild to moderate dehydration?
Evidence from three randomized controlled trials in pediatric patients with mild to moderate dehydration secondary to gastroenteritis, suggests that ondansetron is effective for decreasing risk of requiring intravenous rehydration and reducing vomiting as compared to placebo, both in combination with oral rehydration solution. In another RCT in which level of dehydration was not described, ondansetron was not superior to placebo for reduction of vomiting. Evidence from a randomized controlled trial in which children were at risk of but with no dehydration did not find ondansetron to be effective as compared to placebo, both in combination with oral rehydration solution.
Evidence from a non-randomized study among children with mild to moderate dehydration secondary to gastroenteritis who were discharged from the emergency department indicated no difference in returns and readmissions to the emergency department within 72 hours, for patients receiving ondansetron compared to those who did not.