Ondansetron: a cost-effective advance in anti-emetic therapy

A cost-effectiveness analysis is one form of full economic evaluation where drug acquisition costs and the costs that are incurred as a result of using a particular treatment are assessed together with clinical efficacy. This paper reviews two such studies. One of the studies was a prospective randomised cost-effectiveness study which compared ondansetron (8 mg i.v. 0, 4 and 8 h following chemotherapy) with metoclopramide (3 mg/kg i.v. followed by an infusion of 0.5 mg/kg/h for 8 h) over the first 24 h following chemotherapy in hospitalised patients receiving highly emetogenic chemotherapy. This study showed that the cost per successfully treated patient (defined in this study as having < or = 1 emetic episode and no adverse events) for these 2 treatments were approximately equal: ondansetron pounds 95 and metoclopramide pounds 92. The second study was an economic evaluation based on data collected over a 5-day period following cyclophosphamide-based chemotherapy given on an outpatient basis for the treatment of breast cancer. Patients received an intravenous dose of 16 mg dexamethasone with either 8 mg ondansetron or 60 mg metoclopramide intravenously before chemotherapy followed by oral dosing with 8 mg ondansetron or 20 mg metoclopramide 3 times daily for 5 days. The costs per successfully treated patient (defined in this study as no vomiting or retching episodes and no anti-emetic-related adverse events during the 5-day period) were comparable: ondansetron pounds 184 and metoclopramide pounds 160. A recent study has established that ondansetron (8 mg) given orally twice daily is as effective as the same dose given 3 times a day. A sensitivity analysis using the cost of an ondansetron twice daily regimen showed that ondansetron is more cost-effective than metoclopramide (pounds 133 vs. pounds 160). These cost effectiveness studies have shown that ondansetron is at least as cost-effective as metoclopramide and simplified ondansetron dosing schedules render ondansetron more cost-effective. These full economic evaluations illustrate that drug acquisition costs can be a misleading guide to the economic impact of antiemetics.