Tropisetron vs ondansetron for prevention of postoperative nausea and vomiting after laparoscopic cholecystectomy: a randomized double-blind,placebo-controlled study

Background: Postoperative nausea and vomiting are observed in increased frequency after laparoscopic surgery. This study was performed in order to compare the efficacy of two 5-hydroxytryptamine-3 (5-HT3) receptor antagonists, ondansetron and tropisetron, in preventing postoperative nausea and vomiting (PONV) after laparoscopic cholecystectomy. Methods: Using a randomized, double-blind study design, 87 ASA I and II patients scheduled for laparoscopic cholecystectomy were randomly assigned to receive 4 mg ondansetron (Group A, n = 29), 5 mg tropisetron (Group B, n = 31), or placebo (Group C, n = 27) intravenously (IV) before induction of anesthesia. The end points evaluated were frequency of nausea, nausea intensity rated on a scale from 1 (mild) to 5 (most severe), frequency of vomiting, and need for rescue antiemetics. These parameters were measured immediately after surgery (0 h), at 3 h, 6 h, and 12 h postoperatively. Results: The frequency of nausea was significantly higher in group A (31.2%) compared to group B (14%) at 12 h postoperatively (p <0.01). However, patients of group A had significantly lower nausea scores at 3 h postoperatively compared to group B. Postoperative vomiting occurred in 13.8% of patients in group A and 9.6% of patients in group B throughout the whole study period (p = n.s.). The need for rescue antiemetics was similar between groups A and B. Both groups were superior to placebo concerning all studied parameters. Conclusion: Our results show that ondansetron may be more effective in controlling nausea intensity during the first 3 h after laparoscopic cholecystectomy, while tropisetron has a longer-acting activity, with a major impact on nausea frequency at 12 h postoperatively.