Multidose Ondansetron after Emergency Visits in Children with Gastroenteritis
Written by: Haroon Karabay, DO; Edited by: Brian Smith, DO, MA, MMsc-Med
Background:
About 2 million children in the United States are treated in emergency departments annually for acute gastroenteritis. 90%-95% of these children have associated vomiting with their symptoms. Ondanestron, a 5-hydroxytryptamine type 3 receptor antagonist, reduces rates of IV fluid administration and incidence of hospital admission when given as a single dose in the emergency department to children with acute gastroenteritis. Prior to this current study, two trials evaluating the efficacy of postdischarge administration of ondansetron. In one trial, postdischarge administration of ondansetron was associated with higher rates of diarrhea and of return visits to the ED. In the other study, the rate of vomiting was lower with postdischarge ondansetron than with placebo but there was no significant difference between the number of return visits.
Although ondansetron is provided upon discharge to reduce symptoms of gastroenteritis, there is very little evidence to support this practice. The aim of this study is to determine whether post-discharge administration of ondansetron is beneficial or not.
The study:
Study type: double-blind, randomized, placebo-controlled trial at six Pediatric Emergency Research Canada tertiary care pediatric emergency departments.
Selection criteria: Children 6 months to less than 18 years of age were eligible for the trial if they had received a diagnosis of acute gastroenteritis and had at least 3 episodes of vomiting in the 24 hours before enrollment in the trial, had had an onset of symptoms less than 72 hours before enrollment, had vomited during the 6 hours preceding enrollment, and had received ondansetron as part of the treatment in the ED.
Procedure: Before discharge from the emergency department, participants were provided with oral ondansetron solution (at a concentration of 4 mg per 5 ml of fluid) or placebo solution in an amount sufficient for six doses (each 0.15 mg per kilogram of body weight, up to a maximum dose of 8 mg). Caregivers were informed of the dose to administer, rounded to the nearest 0.1 ml. Caregivers were instructed to provide a repeat dose should vomiting occur within 15 minutes after the solution was administered and to discard the solution 48 hours after enrollment. Caregivers administered the trial solution as needed for ongoing vomiting or nausea, with a maximum frequency of every 8 hours. Caregivers completed a diary tracking administration of the solution and associated indications over the 7-day trial period. The same protocol was followed in hospitalized participants.
Primary outcome: moderate-to-severe gastroenteritis, defined by a total score of 9 or higher on the modified Vesikari scale (scores range from 0 to 20, with higher scores indicating more severe disease) during the 7 days after enrollment
Secondary outcomes: included the presence and duration of vomiting (defined as the time from enrollment to the last vomiting episode); the number of vomiting episodes in the 48 hours after enrollment; unscheduled visits to a health care provider owing to vomiting, diarrhea, dehydration, fever, abdominal pain, or fluid refusal within 7 days after enrollment; administration of intravenous fluids within 7 days after enrollment; and caregiver satisfaction as measured on a five-point Likert scale on the day 7 survey.
Results:
As can be seen by the chart, the percentage of participants with moderate-to-severe gastroenteritis in the 7 days after enrollment was lower in the ondansetron group than the placebo group. Incidence of adverse events was similar.
Conclusion: Providing ondansetron on an as-needed basis to children after an ED visit for gastroenteritis-associated vomiting reduced the risk of moderate-to-severe gastroenteritis after discharge.