Comparison of Two Different Doses of Ondansetron plus Dexamethasone in the Prophylaxis of Cisplatin-lnduced Emesis

This study was conducted to evaluate the efficacy of two different doses of ondansetron (8 mg vs. 24 mg) plus dexamethasone in the prevention of cisplatin (CDDP)-induced emesis and nausea (acute and delayed). The persistence of the anti-emetic efficacy during the second cycle of chemotherapy was also assessed. Eighty patients receiving high-dose CDDP (>80 mg/m2) were randomized to have either ondansetron 8 mg plus dexamethasone 20 mg (8 mg group) or ondansetron 24 mg plus dexamethasone 20 mg (24 mg group), given intravenously as a single dose before the CDDP infusion. From days 2-5, all patients received oral ondansetron 8 mg twice daily. Seventy-five patients (38 in the 8 mg group and 37 in the 24 mg group) were evaluable for analysis. Among these, there were 24 patients who received ifosfamide (IFO) on the 2nd day of treatment; these patients were evaluated separately for delayed emesis. Complete protection from acute emesis was obtained in 26 (68.4%) and 26 (70.3%) patients, in the two groups, respectively. Complete protection against acute nausea was achieved in 23 (60.5%) and 24 (64.9%) patients, respectively. With respect to the delayed emesis, complete protection was achieved in 14 (56%) and 13 (50%) patients not receiving IFO and in 4 (30.8%) and 3 (27.3%) of those receiving IFO. The figures for the delayed nausea were: 12 (48%) and 13 (50%), 2 (15.4%) and 2 (18.2%), respectively. Similar protection against emesis and nausea was recorded during the second cycle of chemotherapy. Both regimens have the same efficacy and thus, taking into account the cost-effectiveness, 8 mg of ondansetron plus dexamethasone in a single intravenous dose should be used for the prevention of high-dose CDDP-induced emesis.