[A Randomized Double-blind Study of Prevention of Postoperative Nausea and Vomiting with Ondansetron, Tropisetron, or Granisetron in Patients Undergoing General Anesthesia]

Objective: To compare the efficacy of different 5-hydroxytryptamine 3 receptor antagonists in the prevention of postoperative nausea and vomiting (PONV) in patients undergoing general anesthesia.

Methods: Totally 360 patients, American Society of Anesthesiologists (ASA) grade I - II, aged 18-75 years, and having received elective operation with endotracheal intubation general anesthesia, were randomly divided into three double-blind groups: ondansetron group, tropisetron group, and granisetron group, with 120 patients in each group. Before anesthesia induction, patients were intravenously given ondansetron (4 mg), tropisetron (5 mg), or granisetron (3 mg), respectively. The episodes of nausea and vomiting were recorded for 24 hours after operation.

Results: No significant differences were observed in the terms of complete inhibition rate of PONV among ondansetron group (70.0%), tropisetron group (68.6%), and granisetron group (72.9%) within 24 hours postoperatively (P >0.05), and so did postoperative nausea incidences (22.5%, 25.4%, and 20.3%, respectively), and postoperative vomiting incidences (10.0%, 13.6%, and 8.5%, respectively) (P > 0.05). No remarked antiemetic-related adverse effects were observed within 24 hours postoperatively.

Conclusion: Intravenous ondansetron (4 mg), tropisetron (5 mg), or granisetron (3 mg) before anesthesia induction can prevent PONV with similar efficacy and safety.