RESUMEN
Background and Objectives - Nausea and vomiting are one of the most commom complications in the postoperative period. The aim of this study was to evaluate the efficacy of ondansetron and prometazine in the prevention of postoperative nause and vomiting. Methods - One hundred and five patients undergoing general anesthesia were distributed in three groups. Group I (control,) did not receive any antiemetic drug. Group II received prometazine 25 mg intramuscularly 30 minutes efore the end of surgery. Group III received ondansetron 4 mg intravenously, 5 minutes before anesthetic induction. The presence and intensity of nausea and vomiting were evalueted until 24 hours after surgery. Results - Incidence of nausea was 80 per cent in the control group; 66 per cent i the prometazine group and 51 per cent in the ondansetron group. There was a significant difference beteen the control and the ondansetron groups. The incidence of vomiting was 66 per cent in the control group, 49 per cent in the prometazine group and 26 per cent in the ondansetron group. There was a significant difference between the ondansetron and the other groups. Conclusion - Ondansetron is an effective drug to prevent postoperative nausea and vomiting