Subtherapeutic INR Values Associated with a Switch to Generic Warfarin

Abstract

While considered bioequivalent by the FDA, switching between Coumadin and generic warfarin may lead to significant changes in the INR, warranting dose alterations due to different content uniformity specifications between Dupont Pharma and the USP. Patients switching between Coumadin and generic warfarin should have their INR monitored more carefully.