This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Hematology, Subject name: Pharmacology
[{'content': 'Which of the following drugs is used in heparin-induced thrombocytopenia \nSelect and explain. \nA. Warfarin, B. Coumarin, C. Lepirudin, D. Enoxaparin', 'role': 'user'}, {'content': "Answer: C \nExplanation: 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).", 'role': 'assistant'}]