Which medications in the drug class Carbonic anhydrase inhibitors are used in the treatment of Acute Angle-Closure Glaucoma (AACG)?

Updated: Jun 20, 2019
  • Author: Albert P Lin, MD; Chief Editor: Inci Irak Dersu, MD, MPH  more...
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Answer

Carbonic anhydrase inhibitors

Reduce secretion of aqueous humor by inhibiting carbonic anhydrase in ciliary body. In acute ACG, may be given systemically but are used topically in patients with refractory open-angle glaucoma. Topical formulations are less effective, and their duration of action is shorter than many other classes of drugs. Adverse effects of topical carbonic anhydrase inhibitors are relatively rare, but they include superficial punctate keratitis, acidosis, paresthesias, nausea, depression, and lassitude.

Acetazolamide (Diamox Sequels)

Inhibits enzyme carbonic anhydrase, reducing rate of aqueous humor formation, which, in turn, reduces IOP. Used for adjunctive treatment of chronic simple (open-angle) glaucoma and secondary glaucoma and preoperatively in acute ACG when delay of surgery desired to lower IOP.

Methazolamide (Neptazane)

Reduces aqueous humor formation by inhibiting enzyme carbonic anhydrase, which results in decreased IOP.

Dorzolamide (Trusopt)

Used concomitantly with other topical ophthalmic drug products to lower IOP. If more than one ophthalmic drug is being used, administer the drugs at least 10 min apart. Reversibly inhibits carbonic anhydrase, reducing hydrogen ion secretion at renal tubule and increases renal excretion of sodium, potassium bicarbonate, and water to decrease production of aqueous humor.

Brinzolamide (Azopt)

Catalyzes reversible reaction involving hydration of carbon dioxide and dehydration of carbonic acid. May use concomitantly with other topical ophthalmic drug products to lower IOP. If more than one topical ophthalmic drug is being used, administer drugs at least 10 min apart.

Dorzolamide HCl/ timolol maleate (Cosopt, Cosopt PF)

Carbonic anhydrase inhibitor that may decrease aqueous humor secretion, causing a decrease in IOP. Presumably slows bicarbonate ion formation with subsequent reduction in sodium and fluid transport.

Timolol is a nonselective beta-adrenergic receptor blocker that decreases IOP by decreasing aqueous humor secretion and may slightly increase outflow facility. Both agents administered together bid may result in additional IOP reduction compared with either component administered alone, but reduction is not as much as when dorzolamide tid and timolol bid are administered concomitantly.


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