Background  

The prophylactic administration of dimenhydrinate (Dramamine) is as effective as the use of ondansetron (Zofran) in preventing postoperative 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) physical statuses I, II, and III patients were randomly assigned to receive either ondansetron 4 mg intravenously (IV) at 17 per dose (group 1) or dimenhydrinate 50 mg IV at17 per dose (group 1) or dimenhydrinate 50 mg IV at 2.50 per dose (group 2) before induction of anesthesia. The end points evaluated were frequency of PONV, need for rescue antiemetics, 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 significance of differences among groups. Of the 128 patients enrolled in this study, 20 were excluded: 15 patients received an additional antiemetic preoperative; 4 were converted to open cholecystectomies; and 1 procedure was aborted due to carcinomatosis. Of the 108 remaining participants, 50 received ondansetron (group 1) and 58 received dimenhydrinate (group 2). Both groups were well matched for demographics including gender, ASA class, and history 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 difference that was not significant. Rates of PONV 24 h after discharge were similar between groups 1 and 2 (10% vs 14%, p=0.397 and 2% vs 5%, p=0.375, respectively).

Conclusion  

Prophylactic administration of dimenhydrinate is as effective as the use of ondansetron in preventing PONV in patients undergoing elective laparoscopic cholecystectomy. Dimenhydrinate is the preferred drug because it is less expensive. With more than 500,000 laparoscopic cholecystectomies performed in the United States each year, the potential drug cost savings from the prophylactic administration of dimenhydrinate instead of ondansetron exceed $7.25 million per year.