title: Measuring direct thrombin inhibitors with routine and dedicated coagulation assays: which assay is helpful?
abstract: The use of direct thrombin inhibitors (DTIs) for prophylactic or therapeutic anticoagulation is increasing because of the predictable bioavailability and short half-life of these DTIs. However, in certain situations, indication of the concentration is warranted. We investigated the effects of 3 DTIs (lepirudin, argatroban, and bivalirudin) in 6 pooled plasma specimens on routine coagulation assays (activated partial thromboplastin time [aPTT], prothrombin time [PT], and thrombin time [TT]) and dedicated DTI assays (Hemoclot, HemosIL, the ecarin clotting time, and a chromogenic ecarin clotting time) on 2 coagulation analyzers. We found routine tests to be nondiscriminative between concentrations of different DTIs in the aPTT. Moreover, for PT and TT, the responses for different DTIs differed. This was similar for ecarin clotting assays. The Hemoclot and HemosIL assays showed identical linear increases for all 3 DTIs. We conclude that dedicated calibrated assays based on a diluted TT (Hemoclot and HemosIL) appear to be the most suitable for monitoring purposes.
authors.affiliation: Clinical Laboratory, Catharina Hospital, Eindhoven, the Netherlands.
authors.forename: Joyce
authors.initials: J
authors.lastname: Curvers
authors.forename: Daan
authors.initials: D
authors.lastname: van de Kerkhof
authors.forename: An K
authors.initials: AK
authors.lastname: Stroobants
authors.forename: Erik-Jan
authors.initials: EJ
authors.lastname: van den Dool
authors.forename: Volkher
authors.initials: V
authors.lastname: Scharnhorst
mesh_terms: D000991:Antithrombins / Q000494:pharmacology*; D001120:Arginine / Q000031:analogs & derivatives; D001777:Blood Coagulation / Q000187:drug effects*; D002863:Chromogenic Compounds; D003955:Diagnostic Tests, Routine / Q000379:methods; D010450:Endopeptidases / Q000494:pharmacology; D005343:Fibrinolytic Agents / Q000494:pharmacology; D006629:Hirudins / Q000494:pharmacology*; D006801:Humans; D010314:Partial Thromboplastin Time / Q000379:methods; D010446:Peptide Fragments / Q000494:pharmacology*; D010875:Pipecolic Acids / Q000494:pharmacology*; D011517:Prothrombin Time / Q000379:methods; D011994:Recombinant Proteins / Q000494:pharmacology; D013449:Sulfonamides; D013917:Thrombin / Q000037:antagonists & inhibitors* / Q000378:metabolism; D013918:Thrombin Time / Q000379:methods
chemical_list: D000991:Antithrombins; D002863:Chromogenic Compounds; D005343:Fibrinolytic Agents; D006629:Hirudins; D010446:Peptide Fragments; D010875:Pipecolic Acids; D011994:Recombinant Proteins; D013449:Sulfonamides; D001120:Arginine; D010450:Endopeptidases; D013917:Thrombin; C020097:ecarin; C031942:argatroban; C074619:bivalirudin; C083544:lepirudin