A double-blind comparison of the efficacy of two dose regimens of oral granisetron in preventing acute emesis in patients receiving moderately emetogenic chemotherapy.

Background: The purpose of this study was to define an optimal administration schedule of granisetron for patients receiving moderately emetogenic chemotherapy by comparing the antiemetic efficacy and safety of 2 mg of the drug administrated orally.
Methods: In this double-blind, randomized, parallel study, 2-dose regimens of oral granisetron were evaluated in 697 adult cancer patients. Patients were stratified by gender and randomized to receive 2 mg oral granisetron, either as a divided dose given 1 hour prior to chemotherapy and 12 hours after the start of chemotherapy, or as a single dose 1 hour prior to chemotherapy at Cycle 1. The primary efficacy endpoints assessed were the percentage of patients with complete response (no nausea, no emesis, and no additional antiemetic medication during the 24-hour post-chemotherapy interval) and the incidence of emesis and nausea. Following completion of Cycle 1, patients were given the opportunity to receive open-label granisetron (2 mg once daily) on the first day of each remaining cycle of chemotherapy.
Results: No statistically significant differences in any of the endpoints were observed between the two treatment groups. Approximately 50% of patients in both treatment groups achieved complete response. The proportion of patients with no episodes of emesis occurred with similar frequency in the two treatment groups. Approximately 52% of patients in either treatment group were free of nausea during the postchemotherapy period. There was no difference between treatment groups regarding the use of antiemetic rescue medication. Finally, the incidence of adverse experiences was similar for both treatment groups.
Conclusions: Both dose regimens of oral granisetron were similarly effective in controlling nausea and vomiting in the 24-hour interval following chemotherapy. Granisetron was well tolerated with few adverse events attributable to the study drug.