RESUMEN
STUDY OBJECTIVE: To examine the safety and effectiveness of a range of single oral doses of dolasetron mesylate for the prevention of postoperative nausea and vomiting. DESIGN: Randomized, double-blind, placebo-controlled trial. SETTING: 32 hospitals. PATIENTS: 789 female ASA physical status I, II, and III patients, ages 18 to 60 years, weighing between 45 and 100 kg, scheduled for major gynecologic surgery (including abdominal hysterectomy, gynecologic laparotomy, or vaginal hysterectomy) with general anesthesia. INTERVENTIONS: 25, 50, 100, or 200 mg oral doses of dolasetron mesylate or placebo were administered 1 to 2 hours before induction of anesthesia. Efficacy was assessed for 24 hours postrecovery by measuring complete response (no emetic episodes, no rescue medication), total response (complete response with no nausea), time to first emetic episode or rescue, and patient visual analog scale evaluations of nausea severity and satisfaction with antiemetic therapy. MEASUREMENTS AND MAIN RESULTS: Complete response rates for the 50, 100, and 200 mg dose groups were statistically greater than placebo (p < or = 0.018). Likewise, total response rates were statistically greater in the 50, 100, and 200 mg dose groups than in the placebo group (p = 0.012). Percentage of patients with no nausea and patient satisfaction scores were significantly higher for each dolasetron dose group than placebo (p < or = 0.047 and p < or = 0.004, respectively). Efficacy peaked at the 50 mg dose. The incidence of adverse events was similar in the placebo (30.1%) and dolasetron groups (29.4%). Headache was the most frequent treatment-related adverse event, with 2% to 5% incidence across groups. Incidence of adverse events did not increase with increasing dolasetron doses. Dose-related decreases in blood pressure at acute time points were not clinically significant. CONCLUSION: Single oral doses of dolasetron, administered 1 to 2 hours before induction of anesthesia, are safe and effective for preventing postoperative nausea and vomiting in this patient sample. Maximal antiemetic response was seen with the 50 mg oral dolasetron dose.