[Anti-emetic effect and safety of ondansetron tablet in double-blind comparison with placebo].

Ondansetron, a selective 5-HT3 receptor antagonist, has already been reported to have a marked effect to alleviate or prevent nausea and vomiting associated with cancer chemotherapy, after its intravenous administration. The present study was planned to examine the usefulness of its tablet form, which was prepared for the convenient use in outpatients receiving chemotherapy. In order to make an objective evaluation of anti-emetic effect and safety of ondansetron 4 mg tablet, this study was conducted in double-blind comparison versus placebo in patients receiving cisplatin at a single dose of 50mg/m2 or higher. Either 4 mg of ondansetron or placebo (lactose tablet) was administered orally once at 2 hrs prior to administration of cisplatin. If any satisfactory anti-emetic effects were not obtained, 4 mg of ondansetron injection was given once intravenously as a rescue medication. The inhibitory effect on nausea and vomiting was assessed in 4 grades as "excellent", "good", "fair" and "poor" based on severity of nausea and number of vomiting that occurred during the first 24hrs after administration of cisplatin. When rescue medication was conducted, the case was assessed as "poor". Ondansetron was significantly superior to placebo in inhibition of nausea and vomiting, in which efficacy rates (excellent+good) of ondansetron and placebo groups were 58.1% (25/43 cases) and 16.7% (7/42 cases), respectively. Number of cases requiring rescue medication with ondansetron injection was obviously greater in placebo group (31 cases) than that in ondansetron group (12 cases). In those patients given ondansetron injection as the rescue medication, satisfactory effects were obtained in 5 cases in ondansetron group and in 18 cases in placebo group. Although side effects including chest itching (ondansetron group), headache and dull headache (placebo group) were observed after the rescue medication with ondansetron injection, these symptoms were not severe and disappeared after 1-2 days. As mentioned above, ondansetron tablet was shown to possess excellent anti-emetic effect on nausea and emesis induced by high dose of cisplatin and to have no problem in safety. Hence ondansetron was proven to be clinically very useful anti-emetic.