Which of the following drugs is used in heparin-induced thrombocytopenia

Ref: Katzung's, 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).