Rx Note

Introduction Blood coagulation means the conversion of liquid blood to a clot. The main event is the conversion by thrombin of soluble fibrinogen to insoluble strands of fibrin, the last step in a complex enzyme cascade . Oral anticoagulants are used mainly for venous thromboembolism (treatment and prevention) and stroke prevention in patients with atrial fibrillation . Bleeding is a common and serious complication of anticoagulant therapy. NOTE: The lack of clinician familiarity with recommended dosing was illustrated in a 2017 report involving over 1500 patients with venous thromboembolism (VTE) who were treated with a DOAC . Warfarin Warfarin is a vitamin K antagonist . Vitamin K is required for the carboxylation (activation) of clotting factors II, VII, IX and X. Warfarin has a narrow therapeutic range and requires careful monitoring of the international normalized ratio (INR) , which is affected by many drugs and changes in the dietary vitamin K . Antidote: Vitamin K Direct ...