PHASE-II TRIAL OF A SINGLE INTRAVENOUS DOSE OF ONDANSETRON IN PATIENTS RECEIVING CISPLATIN GREATER-THAN-OR-EQUAL-TO-100 MG/M2

Ondansetron, a serotonin antagonist antiemetic, controls emesis caused by cisplatin when given as multiple 0.15 mg/kg dosages in a variety of administration schedules. This trial evaluated a single 0.45 mg/kg i.v. dose of ondansetron in 21 cancer patients receiving cisplatin at doses greater-than-or-equal-to 100 mg/m2 as initial chemotherapy. Twenty-five percent of patients had no emetic episodes (95% confidence interval: 9-49%), and 45% had two or fewer emetic episodes (95% confidence interval: 23-69%). No significant adverse effects were seen. In prior trials at this institution in similarly treated patients, ondansetron given in three divided doses yielded a 42% no emesis rate. In this trial a single i.v. 0.45 mg/kg dose of ondansetron prevented emesis in 25% of patients receiving initial cisplatin greater-than-or-equal-to 100 mg/m2. For this dose of cisplatin and ondansetron, the observed emesis complete control rate was lower than that previously seen using multiple dose schedules.