Tropisetron in the prevention of acute and delayed nausea and vomiting over six courses of emetogenic chemotherapy

Tropisetron (Navoban") 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%).