Dorzolamide and Timolol

COSOPT ® is indicated for the reduction of elevated intraocular pressure (IOP) in patients with open-angle glaucoma or ocular hypertension who are insufficiently responsive to beta-blockers (failed to achieve target IOP determined after multiple measurements over time). The IOP-lowering of COSOPT administered twice a day was slightly less than that seen with the concomitant administration of 0.5% timolol administered twice a day and 2% dorzolamide administered three times a day. COSOPT is a combination of dorzolamide hydrochloride, a carbonic anhydrase inhibitor, and timolol maleate, a beta-adrenergic receptor blocking agent, indicated for the reduction of elevated intraocular pressure (IOP) in patients with open-angle glaucoma or ocular hypertension who are insufficiently responsive to beta-blockers.

COSOPT is comprised of two components: dorzolamide hydrochloride and timolol maleate. Each of these two components decreases elevated intraocular pressure, whether or not associated with glaucoma, by reducing aqueous humor secretion. Elevated intraocular pressure is a major risk factor in the pathogenesis of optic nerve damage and glaucomatous visual field loss. The higher the level of intraocular pressure, the greater the likelihood of glaucomatous field loss and optic nerve damage. Dorzolamide hydrochloride is an inhibitor of human carbonic anhydrase II. 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 dose is one drop of COSOPT in the affected eye(s) two times daily. If more than one topical ophthalmic drug is being used, the drugs should be administered at least five minutes apart.

COSOPT is contraindicated in patients with: Bronchial asthma or a history of bronchial asthma, severe chronic obstructive pulmonary disease. Sinus bradycardia, second or third degree atrioventricular block, overt cardiac failure, cardiogenic shock. Hypersensitivity to any component of this product.

Potentiation of Respiratory Reactions Including Asthma. Cardiac Failure. Sulfonamide Hypersensitivity. Obstructive Pulmonary Disease. Increased Reactivity to Allergens. Potentiation of Muscle Weakness. Masking of Hypoglycemic Symptoms in Patients with Diabetes Mellitus. Masking of Thyrotoxicosis. Renal and Hepatic Impairment. Impairment of Beta-Adrenergically Mediated Reflexes During Surgery

The most frequently reported adverse reactions were taste perversion (bitter, sour, or unusual taste) or ocular burning and/or stinging in up to 30% of patients. Conjunctival hyperemia, blurred vision, superficial punctate keratitis or eye itching were reported between 5 to 15% of patients.

Potential additive effect of oral carbonic anhydrase inhibitor with COSOPT. Potential acid-base and electrolyte disturbances. Concomitant use with systemic beta-blockers may potentiate systemic beta-blockade. Oral or intravenous calcium antagonists may cause atrioventricular conduction disturbances, left ventricular failure, and hypotension. Catecholamine-depleting drugs may have additive effects and produce hypotension and/or marked bradycardia. Digitalis and calcium antagonists, may have additive effects in prolonging atrioventricular conduction time. CYP2D6 inhibitors may potentiate systemic beta-blockade.

Store at 20° to 25°C (68° to 77°F). Protect from light.