Effects of Pentasaccharide (Fondaparinux) and Direct Thrombin Inhibitors on Coagulation Testing

Abstract Context.—Direct thrombin inhibitors (DTIs) and fondaparinux represent a new class of anticoagulants. The effects of DTIs on activated partial thromboplastin time and prothrombin time measurements have been reported previously, but there are limited data on the impact of these anticoagulants on other coagulation tests. Objective.—To determine the effects of fondaparinux and 3 DTIs (argatroban, bivalirudin, and lepirudin) on miscellaneous coagulation tests. Design.—Bivalirudin, lepirudin, argatroban, and fondaparinux were added to pooled normal plasma and tested for fibrinogen, antithrombin (thrombin and Xa substrate methods), plasminogen, protein C (clot and chromogenic methods), protein S, von Willebrand factor, D-dimer, lupus anticoagulant testing (dilute Russell viper venom test [DRVVT] with ratio), and factors II, IX, and X activities. Results.—We found no drug interference on antithrombin, plasminogen, chromogenic protein C, von Willebrand factor, or D-dimer results. All DTIs falsely decrease...