Formulary and economic considerations in the selection of antiplatelet agents

A pharmacoeconomic model for evaluating antiplatelet therapies is described. In order to conduct a pharmacoeconomic analysis, it is important to understand the course of the disease under study and the prevention and treatment options, identify the associated economic consequences, develop concomitant strategies, and target high-yield decisions. The steps of a pharmacoeconomics-based decision are defining the pharmacoeconomic problem, creating a cross-functional team, determining the study's perspective, determining the treatment alternatives and outcomes, selecting the appropriate pharmacoeconomic method, placing a monetary value on outcomes, identifying resources and data sources, establishing probabilities of outcomes, using decision analysis, undertaking a cost or sensitivity analysis, presenting the results, developing and implementing a policy or clinical intervention based on the results, educating health care professionals about the new policy or intervention, and documenting the quality of care and potential cost savings through follow-up. Clopidogrel is given as an example. The composite endpoint of myocardial infarction, stroke, or vascular death has been shown to be 8.7% lower with clopidogrel than with aspirin in patients with recent myocardial infarction, recent ischemic stroke, or symptomatic peripheral arterial disease. Clopidogrel costs more than aspirin but may be considered as first-line therapy for high-risk patients, patients who are allergic to aspirin, or patients who cannot tolerate the gastrointestinal effects of aspirin. Cost-effectiveness analyses can be used to support formulary decisions about which antiplatelet agent should be used; the use of a particular agent ultimately also depends on efficacy, safety, pharmacodynamics, patient-specific factors, and relative direct and indirect costs.