Effect of oral ondansetron in children presenting with acute diarrhoeal illness and vomiting with some dehydration
Background: Each year, approximately 700,00 deaths occurring worldwide as a result of acute diarrhoeal illness among children under five years of age. Emesis in acute diarrheal illness is both a direct cause of fluid loss and a significant deterrent to Oral Rehydration Therapy (ORT). An effective treatment of emesis can therefore improve successful ORT and this will not only reduce mortality from diarrhoeal illnesses but also reduce requirement for IV rehydration and hospital admissions. Single dose oral ondansetron has been shown to significantly reduce vomiting in children with acute diarrhoeal illness and therefore improve successful ORT and reduce the requirement for IV rehydration and hospital admissions. No local data exists on the use of ondansetron for vomiting in children with acute diarrhoeal illness. Objectives: The primary objective was to determine the effect of ondansetron in reducing the rate of ORT failure and therefore hospitalization for intravenous rehydration in children presenting with an acute diarrhoeal illness accompanied by vomiting and some dehydration. The secondary objectives were to compare persistence of vomiting and diarrhoea and the rate of hospital revisits 48 hours after the administration of ondansetron or placebo. Methods/Design: This was a prospective randomized double blinded placebo controlled trial. We enrolled children between the ages of 6 and 59 months who presented with an acute diarrhoeal illness accompanied by vomiting and some dehydration at the PEU. Children who fulfilled the criteria for inclusion were enrolled after informed consent was obtained from their parents. They were then randomized to receive either oral ondansetron or placebo in addition to the standard treatment prescribed by the primary clinician. We measured the number of children who failed ORT and thus required admission for IV rehydration and followed up all enrolled patients 48 hours later to measure vomiting and diarrhoea episodes, and number of revisits to a health facility. Baseline characteristics were compared by the chi-square test for proportions and by analysis of variance for continuous variables. Relative risk and 95% confidence intervals are used for categorical data, while means and standard deviations are used for continuous data. The data obtained was analyzed using STATA software according to the intention to treat principle. Results: Baseline characteristics for the two groups i.e. ondansetron and placebo groups were found to be similar. The number of children that failed ORT and thus required hospitalization for IV Rehydration was 18.7% less in those who received oral ondansetron compared to placebo i.e. 3.3% Vs. 22% 7 respectively (i.e. RR 0.17, 95% CI 0.04 - 0.73, P <0.01). Children who received oral ondansetron vs. placebo also had significantly fewer episodes of vomiting i.e. 0.7 vs. 1.4 mean episodes during ORT and 0.27 vs. 0.5 mean episodes at 24 hours of follow up respectively. Proportion of children who had persistent vomiting during the ORT period was significantly higher in the children who received placebo (72.9%) compared to those who received ondansetron (48.3%). There was no significant difference in the number of diarrhoeal episodes between the two groups for up to 48 hours after receiving the drug. Conclusions: Single dose oral ondansetron is associated with fewer vomiting episodes during ORT and hence fewer rates of ORT failure in children with vomiting in an acute diarrhoeal illness. Single dose oral ondansetron is not associated with increased episodes of diarrhoea and is a useful therapy in the management of children with vomiting in an acute diarrhoeal illnesses and some dehydration.