ONDANSETRON AND TROPISETRON WITH DEXAMETHASONE IN THE PROPHYLAXIS OF ACUTE VOMITING INDUCED BY NONCISPLATIN-CONTAINING CHEMOTHERAPY

Forty-seven patients receiving non-cisplatin-containing chemotherapy were entered in a prospective study in which the efficacy of ondansetron plus dexamethasone and tropisetron plus dexamethasone in the prophylaxis of acute vomiting was evaluated. Thirty-nine patients were evaluable for cross-over analysis. During the 24 hours following the start of chemotherapy, 97% of patients on ondansetron plus dexamethasone reported total control of vomiting compared with 82% of those on tropisetron plus dexamethasone (p = 0.026). Thus, both 5-HT3- receptor antagonists combined with dexamethasone were highly effective in controlling acute vomiting induced by non-cisplatin-containing chemotherapy. The observed difference between the treatments may be caused by different dose schedules of ondansetron and tropisetron. A double-blind design with equal number of placebo-controlled administrations is needed to ascertain whether there is a significant pharmacological difference between ondansetron and tropisetron.