[New antithrombotic drugs (excluding plasminogen activators]

New platelet antagonists act on the activation by ADP (clopidogrel, ATP analogue) or on the mechanism of aggregation itself, by binding to the IIb/IIIa glycoprotein complex. The new anticoagulants are as follows: saccharide structures such as danaparoïd and the pentasaccharide of antithrombin binding, and direct thrombin inhibitors, such as recombinating hirudines (desirudine, lepirudine), bivalirudine, melagatran.... Other molecular targets are possible, both at platelet and blood clotting levels but, for the moment, the dilemma remains and reinforcement of antithrombotic activity goes hand in hand with a greater decrease in the defensive mechanisms against bleeding. In general, there is no antidote and the products are often associated, which increases the risk of haemorrhage. The research and development in this field are handicapped by the lack of biological tools for pertinent, homogenous, reproducible evaluation of the effects on haemostasis. The present tendency is to do without biological monitoring for adapting dosage in favour of optimisation of the impact in a given situation, perhaps, above all, with respect to the preceding problem.