Antiemetic efficacy of droperidol or metoclopramide combined with dexamethasone and diphenhydramine. Randomized open parallel study.

We have performed an open parallel randomized study of the efficacy of two antiemetic drug combinations. Dexamethasone (10 mg i.v.), diphenhydramine (25 mg i.v.), and metoclopramide (3 mg/kg, 15 min i.v.) or droperidol (1.25 mg slow push) were given 30 min before and 90 min after start of chemotherapy. Thirty-six patients treated with cisplatin-based regimens (30 mg/m2 x 3 days or 60 mg/m2 day 1 only), have been observed for 48 h after their last chemotherapy. Twelve (67%, confidence interval 95%: 41-87%) experienced no vomiting while on metoclopramide and 11 (61%, confidence interval 36-83%) were protected by droperidol. Further patient accrual was stopped because of side effects in one study arm. Moderate sedation (difficulty to keep up a conversation) was observed in 48% of those on metoclopramide versus 14% of those on droperidol (p less than 0.05). We conclude that low-dose droperidol combinations can offer antiemetic protection for patients treated with moderate-dose cisplatin-based chemotherapies. In view of the potential for severe long-term neurologic problems due to metoclopramide or droperidol, these and similar drugs should be used at the lowest possible dose.