dorzolamide 20 MG/ML Ophthalmic Solution

INDICATIONS AND USAGE Dorzolamide hydrochloride ophthalmic solution, 2% is indicated in the treatment of elevated intraocular pressure in patients with ocular hypertension or open-angle glaucoma. Dorzolamide hydrochloride ophthalmic solution is a carbonic anhydrase inhibitor indicated in the treatment of elevated intraocular pressure in patients with ocular hypertension or open-angle glaucoma. ( 1 )

DOSAGE AND ADMINISTRATION The dose is one drop of Dorzolamide Hydrochloride Ophthalmic Solution in the affected eye(s) three times daily. Dorzolamide Hydrochloride Ophthalmic Solution may be used concomitantly with other topical ophthalmic drug products to lower intraocular pressure. If more than one topical ophthalmic drug is being used, the drugs should be administered at least five minutes apart. The dose is one drop of Dorzolamide Hydrochloride Ophthalmic Solution in the affected eye(s) three times daily. Dorzolamide Hydrochloride Ophthalmic Solution may be used concomitantly with other topical ophthalmic drug products to lower intraocular pressure. ( 2 )

WARNINGS AND PRECAUTIONS • Sulfonamide Hypersensitivity ( 5.1 ) • Bacterial Keratitis ( 5.2 ) • Corneal Endothelium ( 5.3 ) • Allergic Reactions ( 5.4 ) • Acute Angle-Closure Glaucoma ( 5.5 ) 5.1 Sulfonamide Hypersensitivity Dorzolamide hydrochloride ophthalmic solution contains dorzolamide, a sulfonamide; and although administered topically, it is absorbed systemically. Therefore, the same types of adverse reactions that are attributable to sulfonamides may occur with topical administration of dorzolamide hydrochloride ophthalmic solution. Fatalities have occurred, although rarely, due to severe reactions to sulfonamides including Stevens-Johnson syndrome, toxic epidermal necrolysis, fulminant hepatic necrosis, agranulocytosis, aplastic anemia, and other blood dyscrasias. Sensitization may recur when a sulfonamide is readministered irrespective of the route of administration. If signs of serious reactions or hypersensitivity occur, discontinue the use of this preparation [see Contraindications ( 4 )] . 5.2 Bacterial Keratitis There have been reports of bacterial keratitis associated with the use of multiple-dose containers of topical ophthalmic products. These containers had been inadvertently contaminated by patients who, in most cases, had a concurrent corneal disease or a disruption of the ocular epithelial surface. 5.3 Corneal Endothelium Carbonic anhydrase activity has been observed in both the cytoplasm and around the plasma membranes of the corneal endothelium. There is an increased potential for developing corneal edema in patients with low endothelial cell counts. Caution should be used when prescribing dorzolamide hydrochloride ophthalmic solution to this group of patients. 5.4 Allergic Reactions In clinical studies, local ocular adverse effects, primarily conjunctivitis and lid reactions, were reported with chronic administration of dorzolamide hydrochloride ophthalmic solution. Many of these reactions had the clinical appearance and course of an allergic-type reaction that resolved upon discontinuation of drug therapy. If such reactions are observed, dorzolamide hydrochloride ophthalmic solution should be discontinued and the patient evaluated before considering restarting the drug [see Adverse Reactions ( 6 )] . 5.5 Acute Angle-Closure Glaucoma The management of patients with acute angle-closure glaucoma requires therapeutic interventions in addition to ocular hypotensive agents.

CONTRAINDICATIONS Dorzolamide hydrochloride ophthalmic solution is contraindicated in patients who are hypersensitive to any component of this product [see Warnings and Precautions ( 5.1 )]. Dorzolamide hydrochloride ophthalmic solution 2% is contraindicated in patients who are hypersensitive to any component of this product. ( 4 , 5.1 )

Mechanism of Action Carbonic anhydrase (CA) is an enzyme found in many tissues of the body including the eye. It catalyzes the reversible reaction involving the hydration of carbon dioxide and the dehydration of carbonic acid. In humans, carbonic anhydrase exists as a number of isoenzymes, the most active being carbonic anhydrase II (CA-II), found primarily in red blood cells (RBCs), but also in other tissues. Inhibition of carbonic anhydrase in the ciliary processes of the eye decreases aqueous humor secretion, presumably by slowing the formation of bicarbonate ions with subsequent reduction in sodium and fluid transport. The result is a reduction in intraocular pressure (IOP). Dorzolamide Hydrochloride Ophthalmic Solution contains dorzolamide hydrochloride, an inhibitor of human carbonic anhydrase II. Following topical ocular administration, Dorzolamide Hydrochloride Ophthalmic Solution reduces elevated intraocular pressure. Elevated intraocular pressure is a major risk factor in the pathogenesis of optic nerve damage and glaucomatous visual field loss.