The Prophylactic Effect of Tropisetron on Epidural Morphine-Related Nausea and Vomiting: A Comparison of Dexamethasone with Saline
Anesthesia and Analgesia
Tropisetron is a 5-hydroxytryptamine subtype 3 receptor antagonist that is primarily used in the prevention of chemotherapy-induced nausea and vomiting. We evaluated the prophylactic effect of tropisetron on postoperative nausea and vomiting associated with epidural morphine. Dexamethasone and saline served as controls. One-hundred twenty women (n ϭ 40 in each of three groups) undergoing abdominal total hysterectomy under epidural anesthesia were enrolled in this randomized, doubleblinded, and
... doubleblinded, and placebo-controlled study. At the end of surgery, Group 1 received IV tropisetron 5 mg, whereas Groups 2 and 3 received dexamethasone 5 mg and saline, respectively. We found that tropisetron did not significantly reduce the occurrence of nausea and vomiting associated with epidural morphine. Dexamethasone, however, reduced the total incidence of nausea and vomiting from 59% to 21% (P Ͻ 0.01) and the percentage of patients requiring rescue antiemetic from 38% to 13% (P Ͻ 0.05). We conclude that IV tropisetron 5 mg did not prevent the occurrence of postoperative nausea and vomiting associated with epidural morphine. IV dexamethasone 5 mg was effective for this purpose. (Anesth Analg 2002;94:749 -53) T ropisetron is a 5-hydroxytryptamine (5-HT 3 ) receptor antagonist that is primarily used in the prevention of chemotherapy-induced nausea and vomiting (1-3). Its elimination half-life (8 -12 h) is longer than that of other 5-HT 3 antagonists (e.g., ondansetron, 3.2-3.7 h; granisetron, 3-4 h) (4 -6). It is also used in the prevention of radiotherapy-induced emesis and postoperative nausea and vomiting (PONV) after general anesthesia. The recommended dose is 5 mg for chemotherapy-and radiotherapyrelated nausea and vomiting and 2 mg for PONV after general anesthesia (1-4). In patients receiving epidural morphine for postoperative pain control, the incidence of nausea and vomiting is frequent (30%-62%) (7, 8) . Because tropisetron provides a significant antiemetic effect in various conditions, it may also be effective in the prevention of epidural morphine-related nausea and vomiting. However, this has never been tested. The aim of the study was to evaluate the prophylactic effect on PONV of tropisetron 5 mg, dexamethasone, and saline in women who after abdominal surgery received epidural morphine for postoperative pain relief. Methods The protocol was approved by the Hospital Committee for Human Investigation, and previous informed consent was obtained from each patient. One-hundred twenty patients, ASA physical status I or II, 35-55 yr old, who were approved to receive epidural anesthesia for abdominal hysterectomy (with or without oophorectomy) were enrolled in a randomized, doubleblinded, and placebo-controlled study. Patients with a history of PONV, motion sickness or gastrointestinal disorders, or major systemic diseases (e.g., hypertension, diabetes mellitus, and morbid obesity) or who had received an antiemetic within 48 h before surgery were excluded. Patients who needed rescue analgesic for pain during surgery were also excluded from the study, and this was considered a failure of epidural catheterization.