Oral anticoagulants: pharmacodynamics, clinical indications and adverse effects

Discovered early in this century consequent to investigations of a bovine hemorrhagic disease, the oral anticoagulants inhibit a post translational modification required for various hepatically derived serine proteases to become active. These include Factors II, V, VII and X. Through their effect on Proteins S and C, the extrinsic pathway is also effected. While most of these agents exist as optically active enantiomers, with differing kinetics and pharmacologic profiles, they are generally administered in the clinic as racemic mixtures. Over the last 45 years, various studies have sought to better evaluate the role of the oral anticoagulation in both prevention and treatment of various types of thrombo-occlusive and -embolic disease. Such exercises have allowed us to better understand the pathophysiology of those diseases as well as to better characterize the pre-thrombotic state.