This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anti-Hypertensive, Subject name: Pharmacology
Which of the following is not true about bosentan - 
Select and explain. 
A. Used in pulmonary hypertension, B. Used in malignant hepatitis, C. Endothelin receptor antagonist, D. All are true
B: Used in malignant hepatitis
Answer: B: Used in malignant hepatitis 
Explanation: Ans. is 'b' i.e., used in malignant hepatitisEndothelin receptor antagonistso There are two endothelin receptor subtypes - ETA and and ETB.o Bosentan is a nonselective endothelin antagonist - blocks both ETA and ETB.o Bosentan is active intravenously and orally.o Bosentan is currently approved for use in pulmonary hypertension.o Tezosentan another nonseiective antagonist is used investigation for the treatment of acute heart failure,o Sitaxentan and ambrisentan are selective ETA,( antagonists.o Phosphoramidon inhibits formation of endothelin by inhibiting endothelin converting enzyme.Remembero Bosentan can cause severe hepatotoxicity - monthly liver function tests should be done,o It is contraindicated in pregnancy.