Randomized crossover comparison of high-dose intravenous metoclopramide versus a five-drug antiemetic regimen

In a randomized open crossover study, the antiemetic efficacy of a five-drug antiemetic regimen consisting of metoclopramide, dexamethasone, diazepam, diphenhydramine, and thiethylperazine was compared to that of high-dose metoclopramide. Thirteen patients treated with cisplatin combination chemotherapy regimens were evaluated. The study was terminated prior to accrual of the planned number of patients because of the statistically significant difference in efficacy between treatments found at interim analysis. The duration of nausea and number of vomiting episodes on the day of chemotherapy were significantly less (p < 0.01) after receiving the five-drug combination. After receiving the five-drug regimen, 77% of the patients did not experience any episodes of vomiting on day 1, and 8% of patients had only one episode. In contrast, only 31% of patients treated with high-dose metoclopramide did not have any episodes of vomiting on day 1, and 61% of the patients had five or more episodes. None of the patients treated with the five-drug regimen required additional antiemetic administration. Although both regimens were, in general, well tolerated, when given the choice of continuing antiemetic therapies, 92% of the patients preferred the five-drug antiemetic combination.