Efficacy of single-dose intravenous dolasetron versus ondansetron in the prevention of postoperative nausea and vomiting

Background: Postoperative nausea and vomiting (PONV) is a significant problem in surgical patients. The 5-hydroxytryptamine(3)-receptor antagonists ondansetron, dolasetron, and granisetron are being used to prevent PONV and avoid the adverse events associated with traditional antiemetics such as antihistaminic agents, anticholinergic agents, and dopamine antagonists. Objective: Because practitioners have taken widely differing approaches to the selection and dosing of agents in this class, this retrospective study assessed the relative efficacy of IV dolasetron and ondansetron in preventing PONV when used according to their approved labeling. Methods: The medical charts of patients who underwent total abdominal hysterectomy or laparoscopic cholecystectomy and received either dolasetron 13.5 mg or ondansetron 4 mg were reviewed. Efficacy was assessed based on the number of episodes of PONV and time to the occurrence of PONV in the 24 hours after surgery. Results: Of 75 medical records reviewed, 59 met the criteria for inclusion in the efficacy analysis. There were no statistically significant between-group differences in demographic or baseline clinical characteristics. The majority of patients were obese (body mass index greater than or equal to 27 kg/m(2)), had no history of either PONV or motion sickness, and underwent total abdominal hysterectomy. PONV occurred in 11 of 25 (44%) patients receiving dolasetron and 18 of 34 (53%) patients receiving ondansetron. Four patients receiving dolasetron experienced PONV in the first 2 hours after surgery, compared with 7 patients receiving ondansetron. Conclusion: There were no significant differences in efficacy between single doses of IV dolasetron 12.5 mg and IV ondansetron 4 mg in the prevention of PONV.