Ondansetron for the prevention of emesis induced by high-dose cisplatin. A multi-center dose-response study

To determine a dose-response relationship of ondansetron for the prevention of emesis induced by high-dose cisplatin and to study the efficacy of the extended dosing schedule of ondansetron during 20 hours after cisplatin administration, 36 patients with malignant neoplasms who had not previously received chemotherapy but who were currently receiving cisplatin were treated. These patients received a six-dose regimen of 0.01 mg/kg (low dose) or 0.18 mg/kg (high dose) of ondansetron. Seven (41%) patients in the high-dose group had no emesis and four (24%) patients had one or two episodes. One (5%) patient in the low-dose group had no emesis and four (21%) patients had one or two episodes. The difference in the number of emetic episodes was significant (P less than 0.02). Fifty percent of the high-dose patients reported no nausea or mild nausea, compared with 11% of the low-dose patients. Clinical adverse events included mild, transient headache and dizziness in the high-dose group and headache and diarrhea in the low-dose group, with no significant laboratory abnormalities. There is a parallel relationship between the ondansetron doses and the antiemetic efficacy. The response rate for the six-dose regimen of 0.18 mg/kg was not superior to that for the previously reported 0.18 mg/kg regimen given in a three-dose schedule in a similar clinical setting.