The aim of this study was to compare antiemetic efficacy of three serotonin antagonists, granisetron, tropisetron and ondansetron, during conditioning for autologous stem cell transplantation (ASCT). Forty-five malignant lymphoma patients (mean age 38 years, M:F 30:15), undergoing the highly emetogenic regimen BEAM prior to ASCT, were randomized to receive IV granisetron (G) 3 mg once a day, IV tropisetron (T) 5 mg once a day, or IV ondansetron (0) 8 mg twice daily, for six days. The treatment groups were comparable with respect to age, sex and previous experience of nausea and/or vomiting. Nausea and/or emesis control failure was defined as a nausea lasting > or = 4 hours and/or > or = 3 episodes of vomiting/24 h, emesis control failure as > or = 3 episodes of vomiting/24 h. Both the period of chemotherapy (6 days) and the whole period of observation (10 days) were evaluated. Nausea and/or emesis control failure occurred in 24% of patients during the period of chemotherapy and in 51% of patients throughout the whole period of observation, while emesis control failed in 2% and 27% of patients, respectively. The efficacy of three serotonin antagonists was comparable during the chemotherapy period (5 patients with nausea and/or emesis control failure in the granisetron group, 2 in the tropisetron group and 4 in the ondansetron group,p = 0.40). When evaluating the whole period of observation, the antiemetic response to G and T was significantly better than to O, nausea and/or emesis control failure having occurred in 7 (47%) patients treated with G, 5 (33%) patients treated with T, and 12 (80%) patients treated with O, p = 0.03. The results concerning emesis control failures were similar, G 4 (27%), T 1 (7%), O 7 (47%), p = 0.04. Headache was the only frequent side effect of serotonin antagonists (30% incidence). All three serotonin antagonists sufficiently controlled nausea and vomiting during high-dose chemotherapy (BEAM) administration in 67-87% of patients. In comparison with ondansetron, both tropisetron and granisetron proved to be more effective after ASCT, when emetogenic factors other than chemotherapy alone participated.

1st Department of Medicine General University Hospital Charles University Prague 2 Czech Republic