Overview
11 DESCRIPTION Dorzolamide Hydrochloride Ophthalmic Solution, USP is a carbonic anhydrase inhibitor formulated for topical ophthalmic use. Dorzolamide hydrochloride, USP is described chemically as: (4 S-trans )-4-(ethylamino)-5,6-dihydro-6-methyl-4 H -thieno[2,3- b ]thiopyran-2-sulfonamide 7,7-dioxide monohydrochloride. Dorzolamide hydrochloride, USP is optically active.
Mechanism of Action
12 CLINICAL PHARMACOLOGY 12.1 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).
Indications
- 1 INDICATIONS AND USAGE Dorzolamide Hydrochloride Ophthalmic Solution 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 for the treatment of elevated intraocular pressure in patients with ocular hypertension or open-angle glaucoma. ( 1 )
Common Doses
- Refer to label
Dosage
2 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.
Contraindications
- 4 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 is contraindicated in patients who are hypersensitive to any component of this product. ( 4 , 5.1 )
Side Effects
- 6 ADVERSE REACTIONS The most frequently reported adverse reactions associated with Dorzolamide Hydrochloride Ophthalmic Solution were ocular burning, stinging, or discomfort immediately following ocular administration (approximately one-third of patients). Approximately one-quarter of patients noted a bitter taste following administration. Superficial punctate keratitis occurred in 10 to 15% of patients and signs and symptoms of ocular allergic reaction in approximately 10%.
Interactions
- 7 DRUG INTERACTIONS Potential additive effect of oral carbonic anhydrase inhibitor with Dorzolamide Hydrochloride Ophthalmic Solution. ( 7.1 ) Potential acid-base and electrolyte disturbances. ( 7.2 ) 7.1 Oral Carbonic Anhydrase Inhibitors There is a potential for an additive effect on the known systemic effects of carbonic anhydrase inhibition in patients receiving an oral carbonic anhydrase inhibitor and Dorzolamide Hydrochloride Ophthalmic Solution. The concomitant administration of Dorzolamide Hydrochloride Ophthalmic Solution and oral carbonic anhydrase inhibitors is not recommended. 7.