INTRAVENOUS DOLASETRON AND ONDANSETRON IN PREVENTION OF POSTOPERATIVENAUSEA AND VOMITING - A MULTICENTER, DOUBLE-BLIND, PLACEBO-CONTROLLEDSTUDY

Background: Intravenous dolasetron mesilate has shown efficacy in the prevention of postoperative nausea and vomiting (PONV) when administer ed as a single dose prior to emergence from anesthesia. This trial com pared intravenous dolasetron and ondansetron for the prevention of PON V when administered at induction of anesthesia. Methods: This double-b lind, placebo-controlled, multicenter trial randomized patients to one of four single IV treatments: placebo, 25 or 50 mg dolasetron, or 4 m g ondansetron, Efficacy was measured by complete response (0 emetic ep isodes and no rescue medication), nausea severity and patient satisfac tion as measured on a visual analog scale (VAS), investigator's rating of nausea severity, and total response (complete response with no nau sea [less than or equal to 5 mm VAS]). Results: 514 patients at 24 sit es were evaluated for efficacy. The 50 mg dolasetron and 4 mg ondanset ron doses were statistically equivalent, and superior to placebo, for all efficacy measures. Complete response rates were 49%, 51%, 71% and 64% for placebo, 25 and 50 mg dolasetron, and ondansetron, respectivel y. Dolasetron 50 mg was statistically superior to 25 mg dolasetron for complete response, total response, VAS maximum nausea, time to first emetic episode, and patient satisfaction. The majority of adverse even ts were of mild-to-moderate intensity. Headache was the most frequentl y reported treatment-related adverse event with a 3%-5% incidence acro ss treatments. Conclusion: When given at induction of anesthesia, 50 m g intravenous dolasetron is equivalent to 4 mg ondansetron and superio r to 25 mg dolasetron anal placebo for the prevention of PONV. All tre atments were safely administered and well tolerated.