Effect of phenprocoumon on monitoring of lepirudin, argatroban, melagatran and unfractionated heparin with the PiCT method.

Prothrombinase-induced clotting time (PiCT) is a clotting-time test for heparins and direct thrombin inhibitors to reduce drawbacks of aPTT. Effects of the direct thrombin inhibitors lepirudin, argatroban, melagatran and of unfractionated heparin (UFH) were investigated in normal and oral anticoagulant plasma samples. Lepirudin showed potentiating interferences with phenprocoumon effects. Melagatran, argatroban and UFH delivered distinct linear additive effects in both plasma sample groups. PiCT ratio reduces differences between both groups with UFH, and argatroban inhibitor-receptor-binding mode plays a role in interaction patterns.