Tropisetron (Navoban(R)) suppresses nausea and vomiting induced by cancer chemotherapy by antagonizing central and peripheral 5-HT3 receptors. In this open-label study, tropisetron was evaluated in 873 patients who were either refractory to antiemetic treatment during previous chemotherapy or at high risk of emesis as a result of current chemotherapy. The most commonly used agents alone or in combination were cyclophosphamide (35%), fluorouracil (30%), carboplatin (24%) and cisplatin (21%). The primary tumors were breast cancer (27%), lung cancer (16%), gynecological cancers (12%) and lymphoma (9%), Tropisetron was administered as a 15 min infusion prior to chemotherapy and an additional oral 5 mg dose was taken by 80% of the patients on subsequent days. During course 1, complete response to tropisetron was obtained in 64% of patients on day 1, 54% on day 2, 63% on day 3, 71% on day 4 and 77% on day 5, Very similar response rates were found for the six chemotherapy courses. There were few failures after complete and partial response, at maximum 3 and 15%, respectively, Moreover, 24-38% of those with partial response and 7-29% of those with failure could achieve a complete response during the following cycle. The treatment was well tolerated, the most frequently reported adverse events being constipation (3.7%) and headache (2.6%). [(C) 1998 Lippincott Williams & Wilkins.].