Phase II trial of a single intravenous dose of ondansetron in patients receiving cisplatin > or = 100 mg/m2. 
Ondansteron, 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 > or = 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 > or = 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.