Mechanism of action of timolol is ?
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.
Nonselective beta blocker
Nonselective alpha blocker
Selective beta 1 blocker
Selective beta 2 blocker