A multicentre, double-blind, randomised trial comparing ondansetron versus ondansetron plus dexamethasone in the prophylaxis of cisplatin-induced delayed emesis

The aim was to compare the efficacy of ondansetron and a combination of ondansetron plus dexamethasone in the prophylaxis of cisplatin-induced delayed emesis over three consecutive courses of chemotherapy. Cancer patients scheduled to receive for the first time cisplatin (>50 mg/m(2)) in combination with other cytotoxic agents, were recruited in a multicentre, randomised, double-blind study and treated with ondansetron 8 mg i.v. and dexamethasone 20 mg i.v. Twenty-four hours after the start of chemotherapy, patients were randomised to treatment either with oral ondansetron 8 mg bd plus placebo on days 2-5 (group A) or with oral ondansetron 8 mg bd plus oral dexamethasone 8 mg bd on days 2-3, and 4 mg bd on days 4 and 5 (group B). Two hundred and thirty-six cancer patients were recruited into the study. Complete protection from delayed vomiting/nausea in group A and group B was Obtained in 50/39% and in 63/42% of patients, respectively in the first course; in 55/34% and in 64/40% in the second and in 49/31% and 60/37% in the third. Logistic regression analysis reveals a statistically significant difference in incidence of emesis between the combination of ondansetron plus dexamethasone and ondansetron alone (P<0.05). The same model, however, shows no difference in incidence of nausea between the two treatment regimens. Ondansetron plus dexamethasone reduces the risk of delayed emesis following cisplatin chemotherapy as compared to ondansetron alone.