Ondansetron compared with metoclopramide in the treatment of established postoperative nausea and vomiting

We have studied 746 males and females undergoing general anaesthesia for any type of surgical procedure in a double-blind, controlled, randomized study. After experiencing at least one nausea and/or one emetic episode in the 6 h after recovery from anaesthesia, patients received either ondansetron 4 mg i.v. or metoclopramide 10 mg i.v. Patients were observed for postoperative nausea and vomiting (PONV) for 24 h after drug administration. Complete control of PONV was achieved more frequently in the ondansetron-treated patients compared with the metoclopramide-treated patients during the 24-h period (59% vs 41% (P < 0.001) and 44% vs 34% (P = 0.006) for emetic episodes and nausea, respectively). Furthermore, ondansetron was associated with greater patient satisfaction than metoclopramide (P < 0.001) with 49% and 32% of patients, respectively, very satisfied. The overall incidence of adverse events was similar in the ondansetron (7%) and metoclopramide (8%) groups. Ondansetron was as well tolerated and more effective than metoclopramide for all assessment criteria in the treatment of established PONV.