Fasting and warfarin

Warfarin has been the dominant oral anticoagulant since its discovery and first clinical application in the middle of the 20th Century (1-2). Due to its mechanism of action that reduces the synthesis of active vitamin Krelated clotting factors, oral intake of vitamin K rich food has a measurable impact on the anticoagulation effect of warfarin. It is therefore conceivable that periods of food abstinence in the form of fasting has long been suspected of affecting warfarin therapy (3).