This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Pharmacology
[{'content': 'Recent oral direct thrombin inhibitor which can be used for prevention of stroke is \nSelect and explain. \nA. Dabigatrin, B. Ximelagatran, C. Lepirudin, D. Saxagliptin', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Refer Katzung 11/e p 594 Ximelagatran was the first viral direct thrombin inhibitor approved, however it was later withdrawn because of hepatotoxicity. Recently a new direct thrombin inhibitor Dabigatrin had been approved for the prophylaxis of stroke and systemic embolism in nonvalvular atrial fibrillation', 'role': 'assistant'}]