In Vitro Effects of Argatroban, Lepirudin, Bivalirudin, and Danaparoid on Fibrin Gel Permeability

ABSTRACT

In the fibrin gel permeability assay, fibrin formation depends on thrombin generated endogenously, giving greater physiological relevance. The present study evaluated the effects of three direct thrombin inhibitors (argatroban, bivalirudin, and lepirudin) and one indirect factor Xa inhibitor (danaparoid) on fibrin gel permeability. Fibrin gels were prepared by adding tissue factor, phospholipids, and CaCl₂ to normal plasma mixed with one of the inhibitors. The permeability constant (Ks) was determined through flow measurements. At concentrations corresponding to plasma levels during antithrombotic therapy, argatroban, bivalirudin, and danaparoid led to similar increases in Ks, by 320 to 370% of the control; in contrast, almost no effect on Ks could be detected for lepirudin. At concentrations above the “plasma-like” levels, the dose–response curve for lepirudin was noticeably steep, whereas those for the other drugs were shallow. This study suggests that argatroban, bivalirudin, and danaparoid have comparable potential to inhibit thrombin or Xa and the consequent coagulation, rendering the fibrin network permeable. The lack of influence on fibrin gel permeability by lepirudin at the “plasma-like” levels may contradict the antithrombotic effect observed in therapy, but the sharp dose–response curve shown at higher drug concentrations corresponds with reports of bleeding complications from lepirudin with overdosages.

KEYWORDS

Thrombin inhibitor - factor Xa inhibitor - fibrin gel permeability - in vitro

REFERENCES

• 1 Weitz J I, Bates S M. New anticoagulants.  J Thromb Haemost. 2005;  3 1843-1853
• 2 Bauer K A. New anticoagulants. In: American Society of Hematology, Education Program 2006: 450-456
• 3 De Caterina R, Husted S, Wallentin L et al.. Anticoagulants in heart disease: current status and perspectives.  Eur Heart J. 2007;  28 880-913
• 4 Blombäck B, Carlsson K, Fatah K et al.. Fibrin in human plasma: gel architectures governed by rate and nature of fibrinogen activation.  Thromb Res. 1994;  75 521-538
• 5 He S, Cao H, Antovic A et al.. Modifications of flow measurement to determine fibrin gel permeability and the preliminary use in research and clinical materials.  Blood Coagul Fibrinolysis. 2005;  16 61-67
• 6 He S, Blombäck M, Jacobsson-Ekman G et al.. The role of recombinant factor VIIa (FVIIa) in fibrin structure in the absence of FVIII/FIX.  J Thromb Haemost. 2003;  1 1215-1219
• 7 Collet J P, Park D, Lesty C et al.. Influence of fibrin network conformation and fibrin fiber diameter on fibrinolysis speed: dynamic and structural approaches by confocal microscopy.  Arterioscler Thromb Vasc Biol. 2000;  20 1354-1361
• 8 Sorensen B, Johansen P, Christiansen K et al.. Whole blood coagulation thrombelastographic profiles employing minimal tissue factor activation.  J Thromb Haemost. 2003;  1 551-558
• 9 Hemker H C, Giesen P, Aldieri R et al.. The calibrated automated thrombogram (CAT): a universal routine test for hyper- and hypocoagulability.  Pathophysiol Haemost Thromb. 2002;  32 249-253
• 10 Harenberg J, Jörg I, Fenyvesi T, Piazolo L. Treatment of patients with a history of heparin-induced thrombocytopenia and anti-lepirudin antibodies with argatroban.  J Thromb Thrombolysis. 2005;  19 65-69
• 11 Selleng K, Warkentin T E, Greinacher A. Heparin-induced thrombocytopenia in intensive care patients.  Crit Care Med. 2007;  35 1165-1176
• 12 Ahmad S, Iqbal O, Ahsan A et al.. Clinical laboratory monitoring of a synthetic antithrombin agent, argatroban, using high performance liquid chromatography and functional methods.  Int Angiol. 1999;  18 198-205
• 13 Cox D S, Kleiman N S, Boyle D A et al.. Pharmacokinetics and pharmacodynamics of argatroban in combination with a platelet glycoprotein IIB/IIIA receptor antagonist in patients undergoing percutaneous coronary intervention.  J Clin Pharmacol. 2004;  44 981-990
• 14 Carroll R C, Chavez J J, Simmons J W et al.. Measurement of patients' bivalirudin plasma levels by a thrombelastograph ecarin clotting time assay: a comparison to a standard activated clotting time.  Anesth Analg. 2006;  102 1316-1319
• 15 Cho L, Kottke-Marchant K, Lincoff A M et al.. Correlation of point-of-care ecarin clotting time versus activated clotting time with bivalirudin concentrations.  Am J Cardiol. 2003;  9 1110-1113
• 16 Westphal K, Martens S, Strouhal U et al.. Heparin-induced thrombocytopenia type II: perioperative management using danaparoid in a coronary artery bypass patient with renal failure.  Thorac Cardiovasc Surg. 1997;  45 318-320
• 17 Das P, Ziada K, Steinhubl S R et al.. Heparin-induced thrombocytopenia and cardiovascular diseases.  Am Heart J. 2006;  152 19-26
• 18 Tardy B, Lecompte T, Boelhen F et al.. Predictive factors for thrombosis and major bleeding in an observational study in 181 patients with heparin-induced thrombocytopenia treated with lepirudin.  Blood. 2006;  108 1492-1496
• 19 Blombäck B, Bark N. Fibrinopeptides and fibrin gel structure.  Biophys Chem. 2004;  112 147-151