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': 'b -blockers are used in all except? \nSelect and explain. \nA. Hypeension, B. Thyrotoxicosis, C. Variant angina, D. All of the above', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is 'c' i.e., Variant angina We all know that attacks of variant angina occur due to coronary vasospasm. So, the drugs which relieve coronary vasospasms will be used in variant angina (C.C.B.'s, Nitrates) b blockers are contraindicated in these patients because 13 blockers, instead of dilating the coronary aeries constrict the coronary aeries (due to unopposed a mediated constriction). Remember, blockers are useful in classical angina. (They cause ourable redistribution of blood)", 'role': 'assistant'}]