This study was conducted to compare the efficacy of a combination of ondansetron and dexamethasone with that of metoclopramide and dexamethasone for prevention of postoperative nausea and vomiting (PONV) in gynecologic patients receiving fentanyl IV-patient controlled analgesia.

One hundred patients were divided into two groups at random. In Group O, 5 mg of dexamethsone was administered after tracheal intubation, while 4 mg of ondansetron was administered at the end of surgery. In Group M, 5 mg of dexamethsone was administered after tracheal intubation and 20 mg metoclopromide was administered at the end of surgery. During the experiment, the PONV was evaluated at regular intervals. In addition, the incidence of nausea, and vomiting and the numerical rating scale (NRS) of nausea was measured (range, 0-10).

The overall incidence of PONV in Group O was 22/50 (44%) while that in Group M was 19/50 (38%). There were no significant differences in the incidence of nausea, moderate to severe nausea (NRS of nausea, 4-10), or vomiting between groups.

Treatment with a combination of 20 mg metoclopramide and 5 mg dexamethasone is an effective, safe, and inexpensive way to prevent PONV when compared to treatment with 4 mg ondansetron and 5 mg dexamethasone.