Monitoring of direct anticoagulants.

In recent years, new anticoagulants directly targeting individual components of the coagulation cascade have been developed. Although there is no need for routine coagulation monitoring with most of these agents, there are several clinical situations where a specific coagulation test should be available. Global coagulation tests react very sensitive to direct thrombin inhibitors or factor Xa inhibitors. However, with most agents, the effects on activated partial thromboplastin time (APTT) and prothrombin time (PT) are not linear and heterogeneous with respect to different reagents. In contrast, chromogenic assays show a good correlation to the pharmacokinetic of a specific agent.