RESUMO
The objectives of this study were to compare the efficacy and safety of orally administered ondansetron 8 mg b.i.d., 24 mg q.d., and 32 mg q.d. in the prevention of nausea and vomiting associated with high-dose cisplatin-based chemotherapy (cisplatin > or = 50 mg/m2). This was a randomized, parallel-group, double-blind study conducted in North America. It was planned that all patients would receive one of the following orally administered ondansetron treatments 30 min before starting cisplatin dosing (administered over < or = 3 h): 8 mg b.i.d. with 8 h between doses (124 patients), 24 mg q.d. (116 patients), and 32 mg q.d. (117 patients). Use of prophylactic corticosteroids was not permitted. During the 24-h study period, the highest complete response rate (no emesis, rescue antiemetic therapy, or withdrawal) occurred in patients who received ondansetron 24 mg q.d.: 76/115 or 66%, as against 68/124 (55%) after ondansetron 8 mg b.i.d. and 64/117 (55%) after ondansetron 32 mg q.d. Complete control of nausea (no nausea, no rescue, no withdrawal) occurred in more patients in the ondansetron 24 mg q.d. group (64/114, 56%) than in the ondansetron 8 mg b.i.d. group (43/121, 36%) or in the ondansetron 32 mg group (55/117, 50%). These results demonstrate that following highly emetogenic cisplatin-based chemotherapy (> or =2 50 mg/m2), oral ondansetron 24 mg q.d. is more effective than 8 mg b.i.d. for overall control of nausea, and at least as effective if not more effective in the control of acute vomiting than 8 mg b.i.d. or 32 mg q.d. Ondansetron 24 mg q.d. was well tolerated, and no new or unexpected adverse events were identified.