Mechanism of action of timolol is ?: (A) Nonselective beta blocker, (B) Nonselective alpha blocker, (C) Selective beta 1 blocker, (D) Selective beta 2 blocker
Answer is A. Ans. is 'a' i.e., Nonselective beta blocker Timolol is a non selective beta blocker (betal + beta 2). Thus when it is used in the treatment of glaucoma it can precipitate an attack of asthma by blocking beta 2 receptors.