Single i.v. bolus dose of ondansetron in the prevention of postoperative nausea and emesis.

In this placebo controlled, double blind multicentre study, the efficacy and safety of a single i.v. bolus dose of ondansetron 4 mg were evaluated in the prevention of postoperative nausea and vomiting (PONV), which remains one of the most unpleasant side effects experienced by patients postoperatively. The study population included patients having general anesthesia and undergoing major gynecological or elective abdominal surgery by laparoscopy. Thirty three percent of placebo-treated patients had at least one emetic episode over 24 hrs compared with 21% in the ondansetron group (p = 0.03). Forty two percent of placebo-treated patients experienced nausea in the 24 hours post-recovery period, compared to 27% of patients treated with ondansetron 4 mg (p = 0.01). Several factors appeared to be associated with an increased risk of developing PONV, namely gender (female), type of surgery (gynecological), experience of previous PONV and duration of anesthesia; the use of propofol was not a significant factor. Ondansetron was well tolerated, with no side effect being reported as a significant problem.