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Clinical data
Trade names Trusopt, others
AHFS/ Monograph
MedlinePlus a602022
Routes of
Topical (eye drops)
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Pharmacokinetic data
Protein binding ~33%
Elimination half-life 4 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
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Chemical and physical data
Formula C10H16N2O4S3
Molar mass 324.43 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 Yes check.svgY
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Dorzolamide, sold under the brand name Trusopt among others, is a medication used to treat high pressure inside the eye including glaucoma. [1] It is used as an eye drop. [1] Effects begin within three hours and lasts for at least eight hours. [1] It is also available as the combination dorzolamide/timolol. [1]


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] [2] Use is not recommended in pregnancy or breastfeeding. [2] 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. [2] In 2017, it was the 281st most commonly prescribed medication in the United States, with more than one million prescriptions. [3] [4] 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. [5] 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.


Dorzolamide lowers intraocular pressure by about 20%. [5] 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. [5]

Related Research Articles

Glaucoma Eye disease in which high intraocular pressure damages the optic nerve

Glaucoma is a group of eye diseases that result in damage to the optic nerve and cause vision loss. The most common type is open-angle glaucoma, in which the drainage angle for fluid within the eye remains open, with less common types including closed-angle glaucoma and normal-tension glaucoma. Open-angle glaucoma develops slowly over time and there is no pain. Peripheral vision may begin to decrease, followed by central vision, resulting in blindness if not treated. Closed-angle glaucoma can present gradually or suddenly. The sudden presentation may involve severe eye pain, blurred vision, mid-dilated pupil, redness of the eye, and nausea. Vision loss from glaucoma, once it has occurred, is permanent. Eyes affected by glaucoma are referred to as being glaucomatous.

Acetazolamide Chemical compound

Acetazolamide, sold under the trade name Diamox among others, is a medication used to treat glaucoma, epilepsy, altitude sickness, periodic paralysis, idiopathic intracranial hypertension, urine alkalinization, and heart failure. It may be used long term for the treatment of open angle glaucoma and short term for acute angle closure glaucoma until surgery can be carried out. It is taken by mouth or injection into a vein. Acetazolamide is a first generation Carbonic Anhydrase Inhibitor and it decreases the ocular fluid and osmolality in the eye to decrease intraocular pressure.

Pilocarpine Medication used to treat glaucoma and dry mouth

Pilocarpine is a medication used to reduce pressure inside the eye and treat dry mouth. As eye drops it is used to manage angle closure glaucoma until surgery can be performed, ocular hypertension, primary open angle glaucoma, and to bring about constriction of the pupil following its dilation. However, due to its side effects it is no longer typically used in the long term management. Onset of effects with the drops is typically within an hour and lasts for up to a day. By mouth it is used for dry mouth as a result of Sjögren syndrome or radiation therapy.

Ciliary body Part of the eye

The ciliary body is a part of the eye that includes the ciliary muscle, which controls the shape of the lens, and the ciliary epithelium, which produces the aqueous humor. The aqueous humor is produced in the non-pigmented portion of the ciliary body. The ciliary body is part of the uvea, the layer of tissue that delivers oxygen and nutrients to the eye tissues. The ciliary body joins the ora serrata of the choroid to the root of the iris.

Betaxolol Chemical compound

Betaxolol is a selective beta1 receptor blocker used in the treatment of hypertension and glaucoma. Being selective for beta1 receptors, it typically has fewer systemic side effects than non-selective beta-blockers, for example, not causing bronchospasm as timolol may. Betaxolol also shows greater affinity for beta1 receptors than metoprolol. In addition to its effect on the heart, betaxolol reduces the pressure within the eye. This effect is thought to be caused by reducing the production of the liquid within the eye. The precise mechanism of this effect is not known. The reduction in intraocular pressure reduces the risk of damage to the optic nerve and loss of vision in patients with elevated intraocular pressure due to glaucoma.

Olopatadine Chemical compound

Olopatadine, sold under the brand name Opatanol among others, is a medication used to decrease the symptoms of allergic conjunctivitis and allergic rhinitis. It is used as eye drops or as a nasal spray. The eye drops generally result in an improvement within half an hour.


Latanoprost, sold under the brand name Xalatan among others, is a medication used to treat increased pressure inside the eye. This includes ocular hypertension and open angle glaucoma. It is applied as eye drops to the eyes. Onset of effects is usually within four hours, and they last for up to a day.

Timolol Chemical compound

Timolol is a beta blocker medication used either by mouth or as eye drops. As eye drops it is used to treat increased pressure inside the eye such as in ocular hypertension and glaucoma. By mouth it is used for high blood pressure, chest pain due to insufficient blood flow to the heart, to prevent further complications after a heart attack, and to prevent migraines.

Dorzolamide/timolol, sold under the brand name Cosopt among others, is a medication used to treat high pressure inside the eye including glaucoma. It is a combination of dorzolamide hydrochloride and timolol maleate. It may be used when a beta blocker, like timolol, is not sufficient alone. It is used as an eye drop.

Brimonidine Chemical compound

Brimonidine is a medication used to treat open-angle glaucoma, ocular hypertension, and rosacea. In rosacea it improves the redness. It is used as eye drops or applied to the skin.

Carbonic anhydrase inhibitor Class of pharmaceuticals

Carbonic anhydrase inhibitors are a class of pharmaceuticals that suppress the activity of carbonic anhydrase. Their clinical use has been established as anti-glaucoma agents, diuretics, antiepileptics, in the management of mountain sickness, gastric and duodenal ulcers, idiopathic intracranial hypertension, neurological disorders, or osteoporosis.


Brinzolamide is a carbonic anhydrase inhibitor used to lower intraocular pressure in patients with open-angle glaucoma or ocular hypertension.

Levobunolol Chemical compound

Levobunolol is a non-selective beta blocker. It is used topically in the form of eye drops to manage ocular hypertension and open-angle glaucoma.


Bimatoprost, sold under the brand name Lumigan among others, is a medication used to treat high pressure inside the eye including glaucoma. Specifically it is used for open angle glaucoma when other agents are not sufficient. It may also be used to increase the size of the eyelashes. It is used as an eye drop and effects generally occur within four hours.

Brimonidine/timolol, sold under the brand name Combigan, is a fixed-dose combination medication eye drop indicated for the treatment of glaucoma. It is a combination of brimonidine and timolol, in concentrations of 0.2% and 0.5% respectively. Both substances work by decreasing the synthesis of aqueous humor.


Tafluprost is a prostaglandin analogue. It is used topically to control the progression of open-angle glaucoma and in the management of ocular hypertension, alone or in combination with other medication. It reduces intraocular pressure by increasing the outflow of aqueous fluid from the eyes.

Glaucoma medication Eye condition medication

Glaucoma medication is divided into groups based on chemical structure and pharmacologic action. The goal of currently available glaucoma therapy is to preserve visual function by lowering intraocular pressure (IOP), below a level that is likely to produce further damage to the nerve.

Ripasudil, a derivative of fasudil, is a rho kinase inhibitor drug used for the treatment of glaucoma and ocular hypertension.

Brinzolamide/brimonidine, sold under the brand name Simbrinza, is a fixed-dose combination medication used to reduce intra-ocular pressure in adults with ocular hypertension or in those with an eye condition known as open-angle glaucoma. It contains brinzolamide and brimonidine tartrate. It is used as an eye drop.

Posner–Schlossman syndrome (PSS) also known as glaucomatocyclitic crisis (GCC) is a rare acute ocular condition with unilateral attacks of mild granulomatous anterior uveitis and elevated intraocular pressure. It is sometimes considered as a secondary inflammatory glaucoma.


  1. 1 2 3 4 5 6 7 8 9 "Dorzolamide Hydrochloride Monograph for Professionals". American Society of Health-System Pharmacists. Retrieved 26 March 2019.
  2. 1 2 3 British national formulary : BNF 76 (76 ed.). Pharmaceutical Press. 2018. p. 1148. ISBN   9780857113382.
  3. "The Top 300 of 2020". ClinCalc. Retrieved 11 April 2020.
  4. "Dorzolamide Hydrochloride - Drug Usage Statistics". ClinCalc. Retrieved 11 April 2020.
  5. 1 2 3 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