Randomized, double-blind comparison of ondansetron versus ondansetron plus metopimazine as antiemetic prophylaxis during platinum-based chemotherapy in patients with cancer

Purpose: To investigate the antiemetic effect and tolerability of the 5- hydroxytryptamine₃ (5-HT₃) antagonist ondansetron plus the dopamine D₂ antagonist metopimazine versus ondansetron alone in patients receiving platinum-based chemotherapy. Patients and Methods: One hundred eleven chemotherapy-naive patients who were scheduled to receive two consecutive courses of platinum-based chemotherapy were randomized between ondansetron 8 mg intravenously (IV) followed by 8 mg orally twice a day plus metopimazine 35 mg/m² as a 24-hour continuous infusion followed by 30 mg orally four times a day for 4 days, or ondansetron plus placebo. The study used a double- blind, crossover, placebo-controlled design. Results: Ninety-four patients completed the crossover. Complete response (CR; no emetic episodes) was obtained on day 1 in 77.7% of the patients who received the combination versus 50.0% of those who received on dansetron alone (P = .00002), and in 51.7% versus 31.0% on days 2 to 6 (P = .0009). The overall CR (days 1 to 6) was 48.9% versus 25.3% (P = .0002). Additionally, significantly less nausea was observed with the combination on day 1 (P = .0002), days 2 to 6 (P = .0001), and days 1 to 6 (P = .00004). Patient preference was 63.6% for the combination and 13.6% for ondansetron alone; 22.7% expressed no treatment preference (P < .0001; therapeutic gain 50.0%; 95% confidence interval [CI], 31.6% to 68.4%). Adverse reactions were mild and without significant differences between the two treatments. Conclusion: Metopimazine plus ondansetron was significantly superior to ondansetron alone, concerning all efficacy parameters assessed, in patients who received platinum-based chemotherapy.