Will the FDA’s 2010 Warfarin Label Changes Finally Provide the Legal Impetus for Warfarin Pharmacogenetic Testing?

June 16, 2012

Due to newer clinical utility study results and the recent availability of warfarin pharmacogenetic testing, the Food and Drug Administration (“FDA”) has modified warfarin’s prescription labeling twice in the past three years. Yet, despite numerous warfarin dosing adverse events resulting from trial and error dosing, many clinicians have been reluctant to prescribe warfarin pharmacogenetic testing to increase dosing accuracy. This disparity stems from conflicts over the interpretations and results of warfarin pharmacogenetic clinical utility studies. Until the federal government implements independent clinical effectiveness testing authorized by the 2010 Patient Protection and Affordable Care Act, manufacturers, health care institutions, and health care clinicians have the unenviable task of sorting through this morass. This article examines the clinical utility of warfarin pharmacogenetic tests, the FDA’s role, and other contributing factors that have an impact on the liability and practice of those responsible for the tests’ implementation.