RESUMO
BACKGROUND: Combined dexamethasone and tropisetron have been reported more effective than a single drug therapy in preventing postoperative nausea and vomiting (PONV). However, the safety use of dexamethasone has been questioned recently because of the risk of secondary adrenal deficiency. Therefore, we hypothesized that combined tropisetron and methylprednisolone, a short-lasting corticoid, might provide effective prophylaxis of PONV with less effect on endogenous cortisol level. METHODS: In this study, 224 women undergoing modified radical mastectomy under general anesthesia were randomly divided into three groups: 1) receiving 10 mg tropisetron alone (T, N.=76); 2) 10 mg tropisetron and 8 mg dexamethasone (TD, N.=73); or 3) 10 mg tropisetron and 40 mg methylprednisolone (TM, N.=75) intravenously. Serum cortisol level, episodes of PONV and the need for rescue antiemetic medication were recorded during first 3 days after surgery. RESULTS: Serum cortisol significantly decreased in group TD (5.42±1.87 µg/dL), compared with group TM (14.38±2.01 µg/dL, P<0.01) and group T (19.52±1.53 µg/dL, P<0.001) in the first day postoperatively. In the first 24 hours, the incidence of vomiting was significantly higher in group T (15.8%), compared with group TD (5.5%, P<0.05) and group TM (5.3%, P<0.05), respectively. The overall request for a rescue antiemetic of group T was significantly higher, compared with group TD and group TM (P<0.05). CONCLUSION: Methylprednisolone-tropisetron combination is more effective than tropisetron alone, and as equally effective as dexamethasone-tropisetron combination for preventing acute PONV in mastectomy.