dorzolamide + timolol (Merck & Co.)

Dorzolamide + timolol is a fixed-dose combination ophthalmic solution used to reduce elevated intraocular pressure (IOP) in patients with open-angle glaucoma or ocular hypertension who are insufficiently responsive to beta-blockers. It consists of dorzolamide, a carbonic anhydrase II inhibitor, and timolol, a non-selective beta-adrenergic receptor blocker. Dorzolamide reduces aqueous humor secretion by inhibiting carbonic anhydrase in the ciliary processes of the eye, while timolol decreases aqueous humor formation. This dual mechanism provides a more significant reduction in IOP than either component used alone. The combination was originally developed by Merck and is marketed under the brand name Cosopt.

Brand names

CosoptCosopt PF

Other names

dorzolamide hydrochloride + timolol maleate ophthalmic solution