Oral treatment with ondansetron in an outpatient setting.

The efficacy and tolerability of twice-daily oral ondansetron treatment, after a single i.v. dose prechemotherapy, was compared with the established three times a day oral supplement regimen for the prophylaxis of nausea and vomiting induced by cyclophosphamide (greater than or equal to 500 mg/m2) in combination with doxorubicin (greater than or equal to 40 mg/m2) or epirubicin (greater than or equal to 40 mg/m2). Additional treatment with ondansetron twice daily or three times daily was equally effective in controlling emesis and nausea. Supplementary twice-daily oral treatment prevented emesis in 73% of patients in the first 24 h and in 65% of patients over 3 days. Both dose schedules were safe and well tolerated. Ondansetron given i.v. before chemotherapy followed by twice-daily (12-hourly) oral dosing has good efficacy in the control of emesis in oncology outpatients.