EFFECT OF TROPISETRON, A 5-HT(3) RECEPTOR ANTAGONIST, ON ANALGESIA AND NAUSEA AFTER INTRATHECAL MORPHINE

We have studied the effect of tropisetron, a 5-HT3-receptor antagonist, on postoperative nausea, vomiting and pain in 54 patients, aged 50-83 yr, after major hip or knee surgery. The patients were given subarachnoid injection of plain 0.5% bupivacaine, mixed with preservative-free morphine 0.3 mg, for surgical and postoperative analgesia. In a double-blind fashion, either tropisetron 5 mg (1 mg ml-1) or saline 5 ml was injected i. v. 30 min after spinal administration of bupivacaine and morphine. The number of patients needing i m. oxycodone for pain relief the total number of oxycodone doses or the mean time to the first im. oxycodone administration did not differ significantly between the two groups. The number of patients who became nauseated or vomited during the observation period did not differ significantly between groups. Seventeen patients had nausea and 11 vomited in the tropisetron group, compared with 20 and 13, respectively, in the control group during the first 24 h.