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
A patient came to the casualty with acute bronchial asthma after treatment for glaucoma. The probable drug may be - 
Select and explain. 
A. Timolol, B. Betaxolole, C. Latanoprost, D. Anticholinesterase
A: Timolol
Answer: A: Timolol 
Explanation: Ans. is 'a' i.e., Timolol o As you all know b, receptors cause bronchodilatation, blockade of b, mediated bronchodilatation can precipitate bronchospasm and acute attack of asthma. o Timolol is a non-selective b -blocker (blocks pi and b 2 receptors). Therefore, it can precipitate acute attack of asthma. o Betaxolo is also a b -blocker. But it is a cardioselective b -blocker (blocks ft, receptors, not (32).