Dorzolamide Hydrochloride/Timolol Maleate Ophthalmic Solution

**Semantic type:** Organic Chemical|Pharmacologic Substance

**Definition:** An ophthalmic combination agent composed of the hydrochloride salt form of dorzolamide, an inhibitor of carbonic anhydrase II, and the maleate salt form of timolol, a propanolamine derivative and a non-selective beta-adrenergic antagonist, with intraocular pressure-reducing activity. Upon topical administration of dorzolamide hydrochloride/timolol maleate ophthalmic solution, dorzolamide targets, binds to and inhibits carbonic anhydrase II, a zinc-containing enzyme that catalyzes the rapid conversion of carbon dioxide and water into carbonic acid, protons and bicarbonate ions, in the eye. This decreases aqueous humor secretion, and reduces sodium and fluid transport. Although the precise mechanism of action of timolol is not clearly established, timolol targets, binds to and inhibits beta adrenoceptors in the ciliary body of the eye which may decrease aqueous humor production.

**Synonyms:** - Cosopt - Cosopt - Dorzolamide Hydrochloride/Timolol Maleate Solution - Dorzolamide/Timolol Ophthalmic Solution