Dorzolamide
Dorzolamide (Trusopt) is an eye-drop medicine used to lower raised pressure inside the eye in open-angle glaucoma and ocular hypertension. This catalogue includes Trusopt and Cosopt, which pairs dorzolamide with timolol.
Key points
- Carbonic anhydrase II inhibition reduces the fluid produced inside the eye, which lowers eye pressure.
- Cosopt combines dorzolamide hydrochloride with timolol, while Trusopt contains dorzolamide alone.
- Using dorzolamide with an oral carbonic anhydrase inhibitor is not recommended because their effects in the body can add together.
What dorzolamide is used for
Dorzolamide is used for Open-angle Glaucoma and Ocular Hypertension, where raised pressure can damage the optic nerve and affect the field of vision. The listed medicines sit within Eye Care and are used to reduce that pressure.
Common questions about dorzolamide
What is the difference between Trusopt and Cosopt?
Trusopt contains dorzolamide hydrochloride as its active ingredient. Cosopt contains dorzolamide plus timolol, a beta-blocker. Both are eye-drop treatments for raised eye pressure, while Cosopt brings together two active ingredients in one formulation.
How does dorzolamide work in the eye?
Dorzolamide blocks carbonic anhydrase II, an enzyme involved in making fluid inside the eye. Less fluid production lowers intraocular pressure, the pressure measured within the eye.

