New oral anticoagulants: their role and future

After 60 years in which warfarin has been the only practical oral anticoagulant, a number of new oral anticoagulants are entering practice. These drugs differ in a several important respects from warfarin; most notably they have a reliable dose-response effect which means they can be given without the need for monitoring. Their simpler metabolism and mode of action also results in fewer interactions with other drugs and with diet. However, some of their other properties such as renal clearance (to varying degrees), short half-life and lack of an available antidote may slow their rate of introduction. Large trials have established their non-inferiority to warfarin in a number of indications and in some cases their superiority. To date they have been licensed for prophylaxis following high risk orthopaedic procedures, non-valvular atrial fibrillation and treatment of venous thromboembolism, but is not clear that they will supplant warfarin in all areas.