A multicenter, double-blind, randomized comparison of oral ondansetron 8 mg b.i.d., 24 mg q.d., and 32 mg q.d. in the prevention of nausea and vomiting associated with highly emetogenic chemotherapy

The objectives of this study were to compare the efficacy and safety of ora lly 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-base d chemotherapy (cisplatin greater than or equal to 50 mg/m(2)). 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 less than or equal to 3 h): 8 mg b.i.d. with 8 h betwee n doses (124 patients), 24 mg q.d. (116 patients), and 32 mg q.d. (117 pati ents). Use of prophylactic corticosteroids was not permitted. During the 24 -h study period, the highest complete response rate (no emesis, rescue anti emetic therapy, or withdrawal) occurred in patients who received ondansetro n 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 n ausea (no nausea, no rescue, no withdrawal) occurred in more patients in th e 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 (greater than or equal to 50 mg/m(2)), 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 vomitin g 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.