Antiemetic efficacy of prophylactic dimenhydrinate (Dramamine) vs ondansetron (Zofran) - A randomized, prospective trial in patients undergoing laparoscopic cholecystectomy

Background: The prophylactic administration of dimenhydrinate (Dramamine) i s as effective as the use of ondansetron (Zofran) in preventing postoperati ve nausea and vomiting (PONV) in patients undergoing elective laparoscopic cholecystectomy. A prospective double-blind randomized study was performed in a tertiary care referral center. Methods: For this study, 128 American Society of Anesthesiology (ASA) physi cal statuses I, II, and III patients were randomly assigned to receive eith er ondansetron 4 mg intravenously (TV) at $17 per dose (group 1) or dimenhy drinate 50 mg TV at $2.50 per dose (group 2) before induction of anesthesia . The end points evaluated were frequency of PONV, need for rescue antiemet ics, need for overnight hospitalization secondary to persistent nausea and vomiting, and frequency PONV 24 h after discharge. Results: Chi-square tests and student's t-test were used to determine the s ignificance of differences among groups. Of the 128 patients enrolled in th is study, 20 were excluded: 15 patients received an additional antiemetic p reoperative; 4 were converted to open cholecystectomies; and 1 procedure wa s aborted due to carcinomatosis. Of the 108 remaining participants, 50 rece ived ondansetron (group 1) and 58 received dimenhydrinate (group 2). Both g roups were well matched for demographics including gender, ASA class, and h istory of motion sickness. The need for rescue antiemetics occurred in 34% of group 1 and 29% of Group 2 (p = 0.376), postoperative vomiting in 6% of group 1 and 12% of group 2 (p = 0.228), and postoperative nausea in 42% of group 1 and 34% of group 2 (p = 0.422). One group 1 patient and two group 2 patients required overnight hospitalization for persistent nausea, a diffe rence that was not significant. Rates of PONV 24 h after discharge were sim ilar between groups 1 and 2 (10% vs 14%, p = 0.397 and 2% vs 5%, p = 0.375, respectively). Conclusions: Prophylactic administration of dimenhydrinate is as effective as the use of ondansetron in preventing PONV in patients undergoing electiv e laparoscopic cholecystectomy. Dimenhydrinate is the preferred drug becaus e it is less expensive. With more than 500,000 laparoscopic cholecystectomi es performed in the United States each year, the potential drug cost saving s from the prophylactic administration of dimenhydrinate instead of ondanse tron exceed $7.25 million per year.