A randomized, double-blind, dose-ranging, pilot study of intravenous granisetron in the prevention of postoperative nausea and vomiting in patients undergoing abdominal hysterectomy

Background and objective: Postoperative nausea and vomiting (PONV) is a frequent and unpleasant experience that may increase postoperative complications and costs. For surgical procedures with a high risk of PONV, prevention is preferable to treatment. In this study, the authors explore the dose-response relationship between granisetron administered just prior to the end of surgery and post-operative nausea and vomiting in patients undergoing abdominal hysterectomy. Methods: This was a randomized, double-blind, placebo-controlled, pilot study of post-operative nausea and vomiting prevention. Patients undergoing elective open abdominal hysterectomy requiring general anaesthesia received a single dose of granisetron 0.1, 0.2 or 0.3 mg or placebo administered approximately 15 min prior to the end of surgery. The primary efficacy end-point was the proportion of patients with no vomiting in the 0-6 h interval following medication administration. No inferential statistics were planned. Results: The proportion of patients with no vomiting episode in the 0-6 h interval after administration of study medication was higher in each granisetron treatment group (> 90%) than in the placebo group (77%). Proportions of patients with no vomiting episodes in the 0-24 h interval were similar across treatment groups. Results of analyses of proportions of patients with no moderate or severe nausea episodes, proportions of those requiring rescue medication and times to first use of rescue medication suggested a treatment effect of granisetron relative to placebo in both the 0-6 and 0-24 h intervals. Similar proportions of patients in each treatment group reported at least one adverse event. Conclusions: Granisetron at doses of 0.1, 0.2 and 0.3 mg administered just prior to the end of surgery suggested a trend of improved efficacy compared to placebo in preventing postoperative nausea and vomiting in the first 6 h after abdominal hysterectomy. This pilot study did not identify a dose-response relationship.