Ondansetron plus metopimazine compared with ondansetron alone in patients receiving moderately emetogenic chemotherapy

Abstract

Background and methods: The serotonin (5-hydroxytryptamine3) antagonists have improved the treatment of acute chemotherapy-induced nausea and vomiting, but their ability to prevent delayed nausea and vomiting seems less pronounced. The results of a preliminary open trial suggested that the addition of a selective dopamine D2 antagonist could improve the antiemetic efficacy of the serotonin antagonists. In a randomized, double-blind, crossover trial, we compared oral treatment with ondansetron (8 mg twice a day) and the dopamine D2 antagonist metopimazine (30 mg four times a day) with treatment with ondansetron alone for three days in 30 patients who had vomited during the previous cycle of chemotherapy. All the patients received moderately emetogenic chemotherapy.

Results: Combination treatment with ondansetron and metopimazine significantly reduced the incidence of acute (P = 0.006) and delayed (P = 0.02) nausea and acute (P = 0.02) and delayed (P = 0.006) vomiting, as compared with treatment with ondansetron alone. Patients had significantly fewer days of nausea (P = 0.03) and vomiting (P = 0.003) if they received combination therapy. Sixty-seven percent of the patients preferred ondansetron and metopimazine, and 33 percent favored ondansetron alone (P = 0.10). Adverse reactions were mild with both regimens. With the exception of constipation, which was reported more frequently with combination therapy (P = 0.03), there were no significant differences in adverse reactions.

Conclusions: Ondansetron plus metopimazine is a highly effective and safe antiemetic regimen that is markedly superior to treatment with ondansetron alone in patients receiving moderately emetogenic chemotherapy.