The effects of dexamethasone on antiemetics in female patients undergoing gynecologic surgery

This randomized, double-blind study compared the effects of dexamethasone plus either droperidol, metoclopramide, or granisetron with each antiemetic alone for preventing postoperative nausea and vomiting (PONV) in 270 female patients undergoing general anesthesia for major gynecological surgery. Patients were randomly assigned to receive either droperidol 1.25 mg (Group D1, n = 45), droperidol 1.25 mg plus dexamethasone 8 mg (Group D2, n = 45), metoclopramide 10 mg (Group M1, n = 45), metoclopramide 10 mg plus dexamethasone 8 mg (Group M2, n = 45), granisetron 40 micrograms/kg (Group G1, n = 45), or granisetron 40 micrograms/kg plus dexamethasone 8 mg (Group G2, n = 45) immediately before the induction of anesthesia. A standard general anesthetic technique and postoperative analgesia were used throughout the study. Complete response, defined as no PONV and no administration of rescue antiemetic medication during the first 24 h after anesthesia, was 49% in Group D1, 60% in Group D2 (P = 0.199 versus Group D1), 51% in Group M1, 62% in Group M2 (P = 0.198 versus Group M1), 80% in Group G1, and 96% in Group G2 (P = 0.025 versus Group G1). Our results suggest that dexamethasone enhances the antiemetic efficacy of granisetron but does not potentiate the other antiemetics-droperidol and metoclopramide-in female patients undergoing major gynecological surgery. Implications: We compared the efficacy of dexamethasone plus three different antiemetics-droperidol, metoclopramide, and granisetron-for the prevention of nausea and vomiting after gynecologic surgery. The granisetron-dexamethasone combination was the most effective for preventing post-operative emetic symptoms.