Cost effectiveness of 5-hydroxytryptamine3 receptor antagonists: a retrospective comparison of ondansetron and granisetron.

As clinical and economic analyses to date have shown clear benefits of using the new 5-hydroxytryptamine3 receptor antagonists (5-HT3RAs) over traditional antiemetics, the choice between them may necessitate the assessment of comparative cost-effectiveness. This paper presents the results of an assessment of the relative cost-effectiveness of two current 5-HT3RAs: ondansetron and granisetron. The analysis was based on a retrospective assessment of the cost and effectiveness (defined as no vomiting and no worse than mild nausea) of these new antiemetics. Efficacy data were based on the results of two recently published directly comparative clinical studies of ondansetron versus granisetron in the treatment of chemotherapy-induced emesis following both single-dose and fractionated chemotherapy. The cost of treatment was derived by combining clinical data from these studies with manufacturers' drug prices, and published costs of drug administration and emetic episodes. Costs for inpatient stay and side-effects were assumed to be equal across both treatment alternatives. The results were expressed in terms of the total cost per patient of emetic treatment and the cost per well-controlled patient. On this basis, granisetron was found to be more than 50% more cost-effective than ondansetron. This result was robust to variation in key assumptions concerning efficacy and cost, although ondansetron would become the more cost-effective if the dose was reduced to one 8 mg i.v., with no concomitant loss of efficacy.