chapter  6
New oral anticoagulants
Pages 14

After more than half a century of anticoagulation with heparin and vitamin K antagonists (VKAs), a new generation of oral anticoagulants is becoming available. Warfarin and its related oral VKAs have been the mainstay for the management and prophylaxis of thrombosis for more than 50 years. Ansell et al.1 have characterized the use of VKAs in clinical practice as (1) having a narrow therapeutic range, (2) exhibiting considerable variability in dose response among patients due to genetic and other factors, (3) being subject to interactions with drugs and diet, (4) having laboratory control that can be difficult to standardize, and (5) requiring an understanding of pharmacokinetics, pharmacodynamics, and good patient communication for maintenance of a sustained therapeutic level (Box 6.1).