Efficacy of ondansetron in prophylaxis of postoperative nausea and vomiting in patients following infratentorial surgery: A placebo-controlled prospective double-blind study

In a prospective double blind placebo-controlled study, 45 patients schedul ed for infratentorial surgery were randomly allocated into two groups. Five patients were later excluded from the study because of various reasons. Ou t of 40 analyzable patients, 20 received IV Ondansetron (4 mg), whereas the other 20 received the matching placebo approximately 1 hour before the ski n closure. After conclusion of surgery and tracheal extubation, all patient s were monitored in the recovery room for post operative nausea and vomitin g (PONV) for 48 hours. The incidence of PONV within the first 24 hours was found to be 50% and 10% in the placebo and ondansetron groups, respectively (p<0.05). After 24 hours, however, both groups were comparable in relation to the incidence of emesis. Rescue antiemetic (RAE) was required in nine ( 45%) patients in the placebo group and in two (10%) patients in the Ondanse tron group (p<0.05). A significantly higher number of patients remained sed ated postoperatively in the Ondansetron group than in the placebo group (p< 0.05). One patient in the Ondansetron group had protracted diarrhea for 48 hours postoperatively. These results indicate that administration of IV Ond ansetron (4 mg) 1 hour before skin closure effectively reduces PONV after i nfratentorial surgery, and does not have significant adverse effects.