Lepirudin Warfarin

From the therapeutic point of view, prophylaxis of thrombosis must be continued after withdrawal of heparin, since even when there is no evidence of thrombosis in association with heparin-induced thrombocytopenia, thrombosis can follow after some days (52). Because of cross-reactivity, low molecular weight heparin should not be used when heparin has been withdrawn because of heparin-induced thrombocytopenia nor should warfarin be used, because of the risk of venous gangrene, at least until the thrombocytopenia has resolved. Patients with life-threatening or limb-threatening thrombosis can be treated with thrombolytic drugs. Current views are that two antithrombotic drugs should be used, for example danaparoid plus lepirudin (58). 

Lepirudin 0.4 mg/kg slow IV bolus, followed by 0.15 mg/kg/h IV infusion Obtain baseline PT, aPTT, CBC, and serum Cr check aPTT 4 hours after initiation and adjust dose to achieve aPTT of 1.5-3.0 times control once stable, monitor aPTTq12h. Initial dose must be reduced in patients with renal impairment. Antihirudin antibodies can occur in up to 40% of patients and can lead to reduced clearance. Concomitant warfarin requires dose adjustment. 

Classification and Prototypes Anticoagulants reduce the formation of fibrin clots. Two major types of anticoagulants are available heparin and its derivatives, which must be used parenterally and the orally active coumarin derivatives (eg, warfarin). The two groups differ in their chemistry, pharmacokinetics, and pharmacodynamics (Table 34-2). Two other anticoagulant proteins are available lepirudin, a recombinant form of hirudin, a protein found in leech saliva and human antithrombin III, a commercial preparation of an endogenous human anticoagulant. 

Conversion of plasminogen to plasmin is brought about by (A) Aminocaproic acid Heparin Lepirudin Reteplase Warfarin... 

Heparin and warfarin are anticoagulants that affect activation or formation of proteins in the clotting cascade. Lepirudin is an inhibitor of thrombin, and aminocaproic acid is an inhibitor, not an activator, of fibrinolysis and the conversion of plasminogen to plasmin. Reteplase is the only thrombolytic drug listed. The answer is (D). 

Use of argatroban with warfarin and related oral anticoagulants has an effect on the measurement of the BVR, and the manufacturer provides equations to adjust for this. Argatroban does not alter warfarin pharmacokinetics. The manufacturers warn of the increased bleeding risks if aigatroban, bivalirudin or lepirudin are used with other anticoagulants. 

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