This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Autonomic nervous system, Subject name: Pharmacology
[{'content': 'Carvedilol is an effective antihypeensive agent that, like propranolol, is capable of blocking beta receptors. An impoant difference between the two drugs is that carvedilol \nSelect and explain. \nA. is available only as eye drops, B. has intrinsic sympathomimetic activity, C. is a selective blocker of cardiac b1 receptors, D. has a1 receptor blocking actions', 'role': 'user'}, {'content': 'Answer: D \nExplanation: a + b ADRENERGIC BLOCKERS Includes Labetalol, Carvedilol. Carvedilol:- It is a b1 + b2 + a1 adrenoceptor blocker; produces vasodilatation due to a1 blockade as well as calcium channel blockade, and has antioxidant propey. It has been used in hypeension and is the b blocker especially employed as cardioprotective in CHF. Oral bioavailability of carvedilol is 30%. It is primarily metabolized and has a t 1/2 of 6-8 hrs. Ref:- kd tripathi; pg num:-151', 'role': 'assistant'}]