Comparison of metoclopramide and metoclopramide plus dexamethasone for complete protection from cisplatinum-induced emesis.

Metoclopramide was compared to a metoclopramide plus dexamethasone combination in patients receiving high-dose cisplatinum. Metoclopramide 2 mg/kg intravenously was given every 2 hours for 4 doses during two consecutive chemotherapy cycles. A randomized double-blind crossover was used with placebo or dexamethasone 20 mg given intravenously before the first metoclopramide dose. Thirty-six patients completed both study arms. There was no difference in mean vomiting episodes (1.92 for metoclopramide versus 1.33 for the combination, p = 0.20). However complete protection (no vomiting episodes) was achieved in 56% receiving the combination but only 36% receiving metoclopramide alone (p less than 0.08). No significant difference in toxicity or patient preference was noted. Late nausea or vomiting lasting 2 to 7 days appeared in 26% of cycles and was associated with but not completely explained by a greater number of acute vomiting episodes. Combination antiemetic therapy can achieve a higher incidence of complete protection from cisplatinum-induced vomiting. However, late nausea and vomiting may require modification of present regimens.