Ondansetron and dexamethasone dose combinations for prophylaxis against postoperative nausea and vomiting.

Background: Patients at high risk of postoperative nausea and vomiting often receive more than one prophylactic antiemetic drug. In this study we sought to determine whether one or more of four dose combinations of dexamethasone and ondansetron was superior in efficacy.

Methods: In a randomized, double-blind trial of four dose combinations, women having day-surgical gynecologic laparoscopy received IV dexamethasone and ondansetron 4 + 4 mg (Group D4/O4, n = 154), 4 + 2 mg (Group D4/O2, n = 151), 2 + 4 mg (Group D2/O4, n = 154), or 2 + 2 mg (Group D2/O2, n = 155).