Novel oral anticoagulant medications: Impact of pharmacodynamic mechanisms on the efficacy and safety

Administration of oral anticoagulant therapy is a mainstay of the prevention of AF -related thromboembolism. Until recently, the only available option for chronic oral anticoagulation therapy was the administration of vitamin K antagonists, however treatment with these medications is limited by a number of factors including, narrow therapeutic window, drug-drug interactions, problems in standardization of laboratory assays for the measurement of anticoagulation intensity, and complex organization of treatment monitoring required for the optimal treatment results. New era in the management of thromboembolism has arrived with the development of novel oral anticoagulant drugs (NOAC s) that act by inhibiting a single anticoagulant protein in the coagulation cascade (either activated factor X or thrombin), thus providing a pharmacodynamic advantage over vitamin K antagonists. The results of clinical trials that have compared NOAC s and vitamin K antagonists in the prevention and treatment of thromboembolism have demonstrated differences between these two groups of drugs regarding both efficacy (thrombosis prevention) and safety (bleeding risk) that could be attributed to a different mechanism of action. These pharmacodynamic differences have an impact on the future development of pharmacological thromboprophylaxis but also enable individualized treatment of the affected patients with respect to their thromboembolic and hemorrhagic risk.