Dorzolamide Hydrochloride 2% Suppliers & Bulk Manufacturers

Available Forms: Eye Drops

Available Strengths: 2%

Reference Brands: Trusopt (USA), Cosopt (USA)

Category: Opthalmology

Dorzolamide is a topical carbonic anhydrase inhibitor used in ophthalmology to lower elevated intraocular pressure in conditions such as open-angle glaucoma and ocular hypertension. It works by inhibiting carbonic anhydrase in the ciliary body of the eye, reducing aqueous humour production and hence decreasing intraocular pressure. Because it is applied directly as an eye drop, systemic side effects are minimal compared to oral CA inhibitors. For patients whose eye pressure remains high on a single agent, it may be used in combination with a beta-blocker (e.g., timolol) to achieve better control.

Product Description:

Dorzolamide is a topical carbonic anhydrase inhibitor. Blocking carbonic anhydrase II in the ciliary epithelium reduces bicarbonate production and the fluid secretion that follows it, so less aqueous humour is made and intraocular pressure falls. It was the first carbonic anhydrase inhibitor that worked topically, which mattered because the oral drugs in this class cause systemic acidosis, tingling and fatigue that many patients cannot tolerate.

It is used three times daily alone, or twice daily when added to a beta-blocker, for open-angle glaucoma and ocular hypertension. Its characteristic complaints are stinging and burning on instillation, because the solution is formulated at an acidic pH to keep the drug dissolved, and a bitter taste as drops drain into the throat. It is a sulfonamide, so it is avoided in serious sulfonamide hypersensitivity, and rare cases of Stevens-Johnson syndrome and blood dyscrasias have been reported. Superficial punctate keratitis occurs in a minority.

Sourcing notes. Off patent, with generics widely available. The fixed combination with timolol is a separate registration and carries much of the market. Preservative-free unit-dose presentations are in demand for patients on multiple long-term drops, and command a premium.