[Clinical evaluation of ondansetron (injection of a single intravenous dose) against nausea and emesis associated with anti-cancer drugs--dose-finding study in patients receiving cisplatin].

We examined anti-emetic effects, safety and the optimal dose of Ondansetron Injection given in a single intravenous dose in patients receiving a single high dose of cisplatin in randomized controlled comparative study using telephone registration. Ondansetron was injected intravenously in a single dose of 4 mg, 8 mg or 12 mg, at 15 minutes before administration of cisplatin. Nausea and emesis were observed for 24 hours after administration of cisplatin. Efficacy rate of inhibitory effects on nausea and emesis were 76% (19/25 cases) in the 4 mg dose group, 57% (12/21 cases) in the 8 mg dose group and 83% (20/24 cases) in the 12 mg dose group, without a statistically significant difference among 3 dose groups. Hence, it was estimated that the low dose of 4 mg was adequate to exert satisfactory anti-emetic effects. No clear relationship between onset time of the initial emetic episode and plasma concentrations of Ondansetron was found in 16 cases of the 4 mg dose group, 11 cases in the 8 mg dose group and 15 cases in the 12 mg dose group. Side effects observed during this study period were headache and diarrhea in 1 case in the 12 mg dose group. Both symptoms were mild and resolved without treatment. No abnormal findings attributable to Ondansetron were observed in clinical laboratory test. From the above, it was considered that Ondansetron given by a single intravenous injection was highly effective to inhibit nausea and emesis induced by cisplatin, and was highly safe. As to the dose, 4 mg once daily was considered to be adequate for prophylaxis of cisplatin-induced nausea and emesis.