A double-blind, placebo-controlled pilot study examining the effectiveness of intravenous ondansetron in the prevention of postoperative nausea and emesis.

STUDY OBJECTIVE

To compare the efficacy and safety profiles of ondansetron and a placebo when infused immediately prior to anesthesia induction for the prevention of postoperative nausea and emesis (vomiting or retching).

DESIGN

Randomized, double-blind, placebo-controlled, parallel, multicenter pilot study.

SETTING

Three U.S. ambulatory surgical facilities.

PATIENTS

One hundred eighty ASA physical status I and II women scheduled to undergo ambulatory gynecologic surgical procedures while receiving general endotracheal anesthesia.

INTERVENTIONS

Ondansetron 8 mg or a placebo (equivalent volume) was given intravenously (IV) prior to anesthesia induction to prevent postoperative nausea and vomiting.

MEASUREMENTS AND MAIN RESULTS

For the first 24 hours following emergency from anesthesia, patients were monitored in the postanesthesia care unit by a research observer and at home via telephone contact and diary cards. More patients in the ondansetron group (62%) than in the placebo group (40%) were emesis-free over the 24-hour study period (p = 0.005). Ondansetron also was more efficacious than the placebo over the 24-hour study period when a surgery duration of more than 45 minutes was considered in the analyses. For all patients, regardless of surgery duration, there was a low degree of nausea during the course of the study. In all instances, the degree of nausea was slightly lower for ondansetron-treated patients than for placebo-treated patients; however, in no instances were the differences statistically significant. Ondansetron and placebo had similar safety profiles as established by laboratory test results, vital sign monitoring, and adverse event reporting.

CONCLUSION

Ondansetron, infused IV before anesthesia induction, appears to be safe and effective when used in the prevention of postoperative nausea and emesis.