Ondansetron Case Study

Ondansetron (Zofran®), a selective 5-HT3 receptor antagonist, is a prescription medication indicated for the prevention and treatment of nausea and vomiting after chemotherapy, radiation, and surgeries.1 Though vomiting is a universal experience, it is of great concern in infants with gastroenteritis, an illness that occurs from infection with a pathogen of bacterial, viral, parasitic, or protozoal origin, characterized by symptoms including nausea, vomiting, fever, and diarrhea.2 The main treatment for these frequently self-limiting symptoms is oral or intravenous rehydration therapy, which replenishes the lost volume and electrolytes, thereby decreasing the likelihood of more complex conditions occurring.2,3 However, the use of off-label

from January 2004 to April 2005 aimed to discover whether administration of oral ondansetron to pediatric patients with gastroenteritis would decrease symptoms of vomiting and dehydration. The 215 patients who met the study’s inclusion criteria received either oral ondansetron (2, 4, or 8 mg ODT based on weight) or placebo followed by one hour of Enfalyte 30 mL every 5 minutes as oral rehydration therapy 15 minutes after dose administration. Those patients who vomited within 15 minutes received another dose of medication. A physician followed up with the patients after oral rehydration therapy and a decision to start intravenous therapy was made. The primary endpoint of the study was the proportion of pediatric patients who vomited while receiving oral rehydration therapy among those who received ondansetron or placebo. Secondary endpoints included the number of vomiting episodes during oral rehydration and the rates of intravenous hydration among each group. It was found that the proportion of pediatric patients who received ondansetron and subsequently vomited during oral rehydration therapy was lower than those patients who received placebo (14% vs. 35%; RR = 0.40, 95% CI 0.26 to 0.61, P < 0.001), the mean number of vomiting episodes (0.18 vs. 0.65; RR = 0.30, 95% CI 0.18 to 0.50, P < 0.001) and rates of intravenous hydration (14% vs. 31%; RR = 0.46, 95% CI 0.26 to 0.79, P = 0.003) were lower in the ondansetron group than in the placebo group, and the amount of oral rehydration fluid consumed was higher in the ondansetron group than in the placebo group (239 mL vs. 196 mL, P < 0.001). Though the study reported no serious adverse events, it was shown that those patients receiving ondansetron had more diarrhea episodes during oral rehydration compared to placebo (1.4 vs. 0.5, P < 0.001). Thus, this trial showed that ondansetron was more effective than placebo in reducing