title: A comparison of dexamethasone, ondansetron, and dexamethasone plus ondansetron as prophylactic antiemetic and antipruritic therapy in patients receiving intrathecal morphine for major orthopedic surgery.
abstract: In a prospective, double-blinded, randomized trial, we evaluated the efficacy of IV (a) dexamethasone 8 mg, (b) ondansetron 8 mg, and (c) dexamethasone 8 mg plus ondansetron 4 mg for the prevention of postoperative nausea, vomiting (PONV), and pruritus in 130 (ASA physical status I to III) patients undergoing elective major orthopedic surgery after spinal anesthesia with hyperbaric 0.5% bupivacaine and intrathecal morphine. After spinal anesthesia, patients were randomized to one of three groups. Failure of PONV prophylaxis in the 24-h postoperative period occurred more frequently in patients who received dexamethasone alone (29 of 40; 73%) compared with those who received either ondansetron alone (23 of 47; 49%) (P = 0.02) or dexamethasone plus ondansetron together (19 of 43; 44%)(P = 0.01). There was no difference in the incidence of failure of prophylaxis of pruritus (70%, 72%, and 70% in dexamethasone 8 mg, ondansetron 8 mg, and dexamethasone 8 mg plus ondansetron 4 mg, respectively) (P > 0.1) in the 24-h postoperative period. We conclude that the administration of dexamethasone 8 mg with ondansetron 4 mg has no added benefit compared with ondansetron 8 mg alone in the prophylaxis of PONV and pruritus.
  
  
  CONCLUSIONS
  Postoperative nausea and vomiting (PONV) and pruritus are common side effects after spinal opioid administration. In this study, dexamethasone 8 mg plus ondansetron 4 mg was as effective as ondansetron 8 mg. The administration of dexamethasone alone was associated with a frequent incidence of PONV, demonstrating a lack of efficacy. This has important cost implications.
authors.affiliation: Department of Anesthesia and Intensive Care Medicine, Cork University Hospital and University College Cork, Ireland. szarvasszilvia@hotmail.com
authors.forename: Szilvia
authors.initials: S
authors.lastname: Szarvas
authors.forename: Ramesh S
authors.initials: RS
authors.lastname: Chellapuri
authors.forename: Dominic C
authors.initials: DC
authors.lastname: Harmon
authors.forename: John
authors.initials: J
authors.lastname: Owens
authors.forename: Damian
authors.initials: D
authors.lastname: Murphy
authors.forename: George D
authors.initials: GD
authors.lastname: Shorten
mesh_terms: D000368:Aged; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D000932:Antiemetics / Q000627:therapeutic use*; D003907:Dexamethasone / Q000627:therapeutic use*; D004311:Double-Blind Method; D004338:Drug Combinations; D005260:Female; D006801:Humans; D007278:Injections, Spinal; D008297:Male; D009020:Morphine / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D017294:Ondansetron / Q000627:therapeutic use*; D019637:Orthopedic Procedures; D010147:Pain Measurement / Q000187:drug effects; D020250:Postoperative Nausea and Vomiting / Q000517:prevention & control*; D011446:Prospective Studies; D011537:Pruritus / Q000517:prevention & control*
chemical_list: D000701:Analgesics, Opioid; D000932:Antiemetics; D004338:Drug Combinations; D017294:Ondansetron; D009020:Morphine; D003907:Dexamethasone