Vitamin K, a cofactor required for the conversion of precursor proteins into active coagulation factors II, VII, IX, and X, is disrupted by warfarin. As a consequence, the vitamin K-dependent proteins exposed to warfarin during their synthesis are rendered dysfunctional. Where coagulation factors have already been completely synthesized prior to warfarin treatment, the drug has no effect. As a result, the coagulation factors that are fully established have to be depleted by way of normal catabolism before the beneficial effects of warfarin become apparent. Warfarin increases both prothrombin time and aPTT.
Was this article helpful?