Clinical data
Trade namesTrusopt, others
Routes of
Topical (eye drops)
ATC code
Legal status
Legal status
Pharmacokinetic data
Protein binding~33%
Elimination half-life4 months
  • (4S,6S)-4-(ethylamino)-6-methyl-7,7-dioxo-5,6-dihydro-4H-thieno[2,3-b]thiopyran-2-sulfonamide
CAS Number
PubChem CID
CompTox Dashboard (EPA)
ECHA InfoCard100.229.271 Edit this at Wikidata
Chemical and physical data
Molar mass324.43 g·mol−1
3D model (JSmol)
  • CCNC1CC(C)S(=O)(=O)c2sc(cc12)S(=O)(=O)N
  • InChI=1S/C10H16N2O4S3/c1-3-12-8-4-6(2)18(13,14)10-7(8)5-9(17-10)19(11,15)16/h5-6,8,12H,3-4H2,1-2H3,(H2,11,15,16)/t6-,8-/m0/s1 checkY
 ☒NcheckY (what is this?)  (verify)

Dorzolamide, sold under the brand name Trusopt among others, is a medication used to treat high pressure inside the eye, including in cases of glaucoma.[1] It is used as an eye drop.[1] Effects begin within three hours and last for at least eight hours.[1] It is also available as the combination dorzolamide/timolol.[1][2]

Common side effects include eye discomfort, eye redness, taste changes, and blurry vision.[1] Serious side effects include Steven Johnson syndrome.[1] Those allergic to sulfonamides may be allergic to dorzolamide.[1][3] Use is not recommended in pregnancy or breastfeeding.[3] It is a carbonic anhydrase inhibitor and works by decreasing the production of aqueous humour.[1]

Dorzolamide was approved for medical use in the United States in 1994.[1] It is available as a generic medication.[3] In 2020, it was the 216th most commonly prescribed medication in the United States, with more than 2 million prescriptions.[4][5] It is a second-generation carbonic anhydrase inhibitor.

Medical uses

Dorzolamide hydrochloride is used to lower excessive intraocular pressure in open-angle glaucoma and ocular hypertension. This drug is able to cross the cornea, reach the ciliary body of the eye, and produce systemic effects on the carbonic anhydrase enzyme within the eye.

Side effects

Ocular stinging, burning, itching and bitter taste.[6] It causes shallowing of the anterior chamber and leads to transient myopia. As a second generation carbonic anhydrase inhibitor, Dorzolamide avoids systemic effects associated with first generation carbonic anhydrase inhibitors such as Acetazolamide, Methazolamide, and Dichlorphenamide.


This section needs expansion. You can help by adding to it. (January 2019)

Dorzolamide lowers intraocular pressure by about 20%.[6] Normally, carbonic anhydrase converts carbonic acid (H2CO3) into bicarbonate (HCO3), releasing a proton (H+) into solution. The H+ is then exchanged for sodium (Na+) ions, which facilitates the production of aqueous humor[citation needed]. By blocking the function of carbonic anhydrase, the Na+/H+ exchange is unable to occur, which leads to a decrease in Na+ in the cell and prevents aqueous humor production[citation needed].


This drug, developed by Merck, was the first drug in human therapy (market introduction 1995) that resulted from structure-based drug design. It was developed to circumvent the systemic side effects of acetazolamide which has to be taken orally.[6]


  1. ^ a b c d e f g h i "Dorzolamide Hydrochloride Monograph for Professionals". American Society of Health-System Pharmacists. Retrieved 26 March 2019.
  2. ^ "Dorzolamide (Ophthalmic Route) Description and Brand Names - Mayo Clinic". Retrieved 2023-11-03.
  3. ^ a b c British national formulary : BNF 76 (76 ed.). Pharmaceutical Press. 2018. p. 1148. ISBN 9780857113382.
  4. ^ "The Top 300 of 2020". ClinCalc. Retrieved 7 October 2022.
  5. ^ "Dorzolamide - Drug Usage Statistics". ClinCalc. Retrieved 7 October 2022.
  6. ^ a b c KD Tripari MD (2004). Essentials of Medical Pharmacology (5th ed.). Jaypee Brothers Medical Publishers(P) Ltd. p. 88. ISBN 81-8061-187-6.

Further reading