[From old to new anticoagulants: the role of the biologist]

Anticoagulant drugs are of great interest to patients and clinical physicians, as well as research scientists. The latter two groups combine their efforts to unravel the related mechanisms of action, as well as means of monitoring and proper dosing. Unfractionated heparin and low molecular weight heparins and vitamin K antagonists have been on board for several decades by now. They act on several clotting factors in certain sequences. Newer drugs, produced by chemical synthesis, act on a more specific target, often factor Xa or factor IIa. These newer anticoagulants have a great convenience in being orally administered and not needing routing laboratory monitoring - which is their main advantage. Hirudine and fondaparinux have been registered for a few years. This year, that is 2008 + 2009, two of these new anticoagulants have been registered and approved for use in Europe and Canada - these are dabigatran etexilate (Pradaxa) and rivaroxaban (Xarelto). Both do not require routine laboratory monitoring. However, coagulation assays for measuring their activity have been studied. A small number of standardized tests should be perfected.