Oral dimenhydrinate versus placebo in children with gastroenteritis: a randomized controlled trial.

To evaluate the efficacy and safety of oral dimenhydrinate in the treatment of acute gastroenteritis. This was a randomized, double-blind, placebo-controlled trial conducted in the emergency department of a pediatric university-affiliated center. Children 1 to 12 years old who presented to the emergency department with at least 5 episodes of vomiting in the previous 12 hours and diagnosed with acute gastroenteritis were block-randomized to receive oral dimenhydrinate (1 mg/kg; maximum: 50 mg) every 6 hours for 4 doses or placebo for 4 doses. The primary outcome measure was treatment failure as defined by the occurrence of ≥ 2 episodes of vomiting in the 24 hours after administration of the first dose of the study medication. During the study period, 209 patients met inclusion criteria, but 50 refused to participate and 7 were missed. Eight participants were lost to follow-up, and 144 were thus included in the primary analysis. Of these patients, 74 were randomized to receive dimenhydrinate and 70 placebo. The proportions of patients showing failure of treatment were similar for both treatment groups: dimenhydrinate, 31% (23 of 74); placebo, 29% (20 of 70) (difference: 0.02 [95% confidence interval: -0.12 to 0.17]). There were no differences between the 2 groups in rates of intravenous cathether insertion, mean number of episodes of vomiting or diarrhea, abdominal pain, nausea, duration of symptoms, revisit rates, or parental absenteeism. The proportions of adverse effects were similar in both groups (53% vs 54%). The prescription of oral dimenhydrinate did not significantly decrease the frequency of vomiting in children with acute gastroenteritis compared with placebo.