Tropisetron for treating established postoperative nausea and vomiting: a randomized, double-blind, placebo-controlled study.
UNLABELLED: Tropisetron can prevent postoperative nausea and vomiting (PONV) at doses smaller than those used to control chemotherapy-induced nausea and vomiting. In this placebo-controlled study, the efficacy and tolerability of three different doses of tropisetron were compared for the treatment of established PONV after surgical procedures in general anesthesia. Of 1513 patients who satisfied inclusion criteria, 314 experiencing PONV during the first 2 h after recovery from anesthesia were treated with one of three different doses of tropisetron (0.5, 2, or 5 mg) or placebo, administered i.v. as a single dose. Patients were then observed during 24 h for efficacy and tolerability. All three doses of tropisetron were significantly better than placebo in controlling emetic episodes and in reducing the need for rescue treatment. There were no significant differences among the three doses. However, in the subgroup of patients who had previous PONV, and in those randomized for nausea alone, the 2-mg and 5-mg doses controlled emetic episodes better than the 0.5-mg dose. All studied doses of tropisetron were well tolerated and did not affect vital signs. We conclude that a single i.v. administration of tropiestron significantly reduces the recurrence of emetic episodes in patients with established PONV after elective surgery with general anesthesia. Its optimal dose seems to be 2 mg. IMPLICATIONS: Three hundred-fourteen patients suffering from postoperative nausea and vomiting received different i.v. doses of a new antiemetic drug, tropisetron, to determine the lowest effective dose. We found that a single i.v. administration of tropisetron significantly reduced postoperative nausea and vomiting after elective surgery with general anesthesia.