<prompt> Which of the following drugs is used in heparin-induced thrombocytopeniaWarfarinCoumarinLepirudinEnoxaparin  <response>: Ref: Katzungs, 11th ed. pg. 593-594 Heparin is a powerful and instantaneously acting anticoagulant, effective both in vivo and in vitro. It acts indirectly by activating plasma antithrombin III The heparin -AT III complex then binds to clotting factors of the intrinsic and common pathways Xa, IIa, IXa, XIa, XIIa and XIIIa and inactivates them. HIT syndrome is a condition which arises as a potential side effect of heparin use where heparin binds with platelet factor 4 and causes thrombocytopenia usually seen 3-4 days after heparin use. To treat this condition, direct thrombin inhibitors are used. Drugs under direct thrombin inhibitors are: Lepirudin, bivalirudin, hirudin, dabigatran, argatroban, melagatran. Enoxaparin: It is low molecular weight heparin Warfarin is oral anticoagulant, which act by inhibiting vitamin K dependent clotting factors Factor II, VII, IX, X. 