Ondansetron for efficient emesis control during total body irradiation.

Ondansetron is a 5-hydroxytryptamine receptor antagonist which has shown activity in the prevention of emesis following cytotoxic and radiation therapy for cancer. We describe our experience using ondansetron in 25 patients undergoing fractionated total body irradiation (TBI) 12 Gy/3 days as conditioning for bone marrow transplantation. Antiemetic efficiency was investigated during the 3 days of TBI prior to high-dose cytotoxic chemotherapy. Twenty-two of the 25 patients (88%) achieved sufficient emesis control with less than three emetic episodes whereas the remaining 12% experienced three to five emetic events during their worst 24-h period. Eleven patients (44%) had complete control with no vomiting at all. Of 75 'patient days', 52 (69%) were without any emesis, 20 (27%) were associated with one to two and only three (4%) with three to five emetic episodes. Headache occurred in four patients (16%). No other significant adverse effects were seen, in particular no extrapyramidal reactions due to ondansetron. Our data confirm that ondansetron plays a major role in the antiemetic management of patients undergoing TBI.