Use of oral and intravenous ondansetron in patients treated with cisplatin.

Ondansetron, a selective 5-HT3 antagonist, has been shown to be effective in preventing chemotherapy-induced nausea and vomiting. From July and August 1991, 25 patients were accrued in a phase II study to assess the efficacy of ondansetron in patients receiving cisplatin-containing chemotherapy. Patients received intravenous cisplatin 100 mg/m2, given either as a 24-hour infusion on day 1 or in divided doses as eight-hour infusions daily on days 1 to 3. Each patient received 24 mg of ondansetron per day for six days. Intravenous dexamethasone 24 mg was given daily on the days of cisplatin infusion. The emetic episodes and degree of nausea were evaluated daily. "Good" control of emesis (0-2 episodes of vomiting) and nausea (mild or no nausea) ranged from 64-100% and 88-100% respectively. Failure in emesis control occurred most frequently on days 3 and 4. Ondansetron was generally well tolerated with only minimal side-effects. One patient developed unexplained encephalopathy which resolved completely. Our results suggest that ondansetron is an effective anti-emetic agent with minimal toxicities. Randomised studies comparing ondansetron against "standard" anti-emetics should be conducted.