This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
[{'content': 'Which of the following is not true about bosentan \nSelect and explain. \nA. Used in pulmonary hypeension, B. Used in malignant hepatitis, C. Endothelin receptor antagonist, D. All are true', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., used in malignant hepatitis Endothein receptor antagonists There are two endothelin receptor subtypes - ETA and and ETB. Bosentan is a nonselective endothelin antagonist - blocks both ETA and ETB. Bosentan is active intravenously and orally. Bosentan is currently approved for use in pulmonary hypeension. Tezosentan another nonselective antagonist is used investigation for the treatment of acute hea failure. Sitaxentan and ambrisentan are selective ETA antagonists. Phosphoramidon inhibits formation of endothelin by inhibiting endothelin conveing enzyme. Remember Bosentan can cause severe hepatotoxicity - monthly liver function tests should be done. It is contraindicated in pregnancy.", 'role': 'assistant'}]