About Timolol Nonselective Beta Adrenergic,Blocker,Ophthalmic- Antiglaucoma,antimigraine. Mechanism of Action of Timolol Timolol is a non selective beta blocker. It inhibits the beta receptors (?2) present in the eye such as in the ciliary body epithelium and blood vessels. This will leads to decreased aqueous production and reduced intraocular pressure. Aqueous humor production is activated by ? receptor mediated cyclic AMP phosphokinase pathway. Beta receptor blockers will decreases the intracellular cyclic AMP level and reduces intraocular pressure. Another mechanism is that Timolol decreases the ocular blood flow which decreases ultrafiltration responsible for aqueous production.