Warfarin Therapy: New Challenges of an Old Drug

摘要: The anticoagulant drug warfarin is a vitamin K antagonist (VKA), coumarin derivative, formed by the racemic mixture of two optically active isomers known Rectus (R) and Sinister (S) enantiomers in equal proportion, being S-warfarin five times more potent. Although still considered mainstay oral treatment, it difficult to manage due its narrow therapeutic index. An inappropriate management patients can lead subtherapeutic or supratherapeutic levels, increasing risk thromboembolic episodes hemorrhagic episodes, respectively. Common indications for use include stroke prevention atrial fibrillation, preventing thrombus formation with heart valves treatment venous thromboembolism. Unlike situations as nonvalvular fibrillation (and factors such hypertension, diabetes ventricular dysfunction), thrombosis pulmonary embolism where there evidence new anticoagulants (dabigatran, apixaban, rivaroxaban, etc), similar remain only option cardiac valve prosthesis requiring anticoagulation.