Cost-effectiveness and efficacy of combined dexamethasone–metoclopramide versus ondansetron in the prevention of postoperative nausea and vomiting in women undergoing myomectomy under spinal anesthesia

Abstract

Background: Postoperative nausea and vomiting (PONV) is a common complication following surgery under spinal anesthesia. The aim of this study was to compare the efficacy and cost-effectiveness of metoclopramide–dexamethasone combination with ondansetron as prophylaxis against PONV in the routine gynecological surgeries amenable to subarachnoid block (SAB). Materials and Methods: Following institutional ethical approval, patients were randomly assigned to receive either ondansetron 4 mg or metoclopramide 10 mg plus dexamethasone 8 mg. All patients had a SAB with 3 ml of 0.5% hyperbaric bupivacaine plus 25 μg of fentanyl. The primary outcome was proportion of patients in both groups with PONV within 24 h from institution of the SAB. Secondary outcome included comparison of severity of PONV between the two study groups, incidence of side effects related to the study drugs (i.e., sedation, headaches, and movement disorder), and cost implication of the study drugs in both groups. Results: One hundred patients were recruited in this study. The overall incidence of PONV for the 24-h period was 10% (n = 5) and 12% (n = 6) for the ondansetron group and the combination group, respectively. Side effects of the study drugs were minimal and comparable in both groups. The cost-effectiveness ratio, evaluated based on the number of women completely free of nausea and vomiting in each group, was higher at ₦ 177.78 for group ondansetron compared to ₦ 113.63 for metoclopramide and dexamethasone combination group. Conclusion: Combined dexamethasone–metoclopramide had comparable clinical effectiveness with lower cost-effectiveness compared to ondansetron for the prevention of PONV in women undergoing myomectomy under SAB.