Timolol

Timolol Maleate Ophthalmic Solution is indicated in the treatment of elevated intraocular pressure in patients with ocular hypertension or open-angle glaucoma.

Timolol maleate is a beta 1 and beta 2 (non-selective) adrenergic receptor blocking agent that does not have significant intrinsic sympathomimetic, direct myocardial depressant, or local anesthetic (membrane-stabilizing) activity. Beta-adrenergic receptor blockade reduces cardiac output in both healthy subjects and patients with heart disease. In patients with severe impairment of myocardial function, beta-adrenergic receptor blockade may inhibit the stimulatory effect of the sympathetic nervous system necessary to maintain adequate cardiac function. Beta-adrenergic receptor blockade in the bronchi and bronchioles results in increased airway resistance from unopposed parasympathetic activity. Such an effect in patients with asthma or other bronchospastic conditions is potentially dangerous.

Timolol Maleate Ophthalmic Solution is available in concentrations of 0.25 and 0.5%. The usual starting dose is one drop of Timolol Maleate Ophthalmic 0.25% Solution in the affected eye(s) twice a day. If the clinical response is not adequate, the dosage may be changed to one drop of 0.5% solution in the affected eye(s) twice a day. Since in some patients the pressure-lowering response to Timolol Maleate Ophthalmic Solution may require a few weeks to stabilize, evaluation should include a determination of intraocular pressure after approximately 4 weeks of treatment with Timolol Maleate Ophthalmic Solution. If the intraocular pressure is maintained at satisfactory levels, the dosage schedule may be changed to one drop once a day in the affected eye(s).

Timolol Maleate Ophthalmic Solution is contraindicated in patients with bronchial asthma, a history of bronchial asthma, severe chronic obstructive pulmonary disease, sinus bradycardia, second or third degree atrioventricular block, overt cardiac failure, cardiogenic shock, or hypersensitivity to any component of this product.

As with many topically applied ophthalmic drugs, this drug is absorbed systemically. The same adverse reactions found with systemic administration of beta-adrenergic blocking agents may occur with topical administration. For example, severe respiratory reactions and cardiac reactions, including death due to bronchospasm in patients with asthma, and rarely death in association with cardiac failure, have been reported following systemic or ophthalmic administration of timolol maleate. Cardiac Failure Sympathetic stimulation may be essential for support of the circulation in individuals with diminished myocardial contractility, and its inhibition of beta-adrenergic receptor blockade may precipitate more severe failure.

The most frequently reported adverse experiences have been burning and stinging upon instillation (approximately one in eight patients). The following additional adverse experiences have been reported less frequently with ocular administration of this or other timolol maleate formulations: Body as a Whole Headache, asthenia/fatigue, and chest pain. Cardiovascular Bradycardia, arrhythmia, hypotension, hypertension, syncope, heart block, cerebral vascular accident, cerebral ischemia, cardiac failure, worsening of angina pectoris, palpitation, cardiac arrest, pulmonary edema, edema, claudication, Raynaud’s phenomenon, and cold hands and feet. Digestive Nausea, diarrhea, dyspepsia, anorexia, and dry mouth. Immunologic Systemic lupus erythematosus.

Although Timolol Maleate Ophthalmic Solution used alone has little or no effect on pupil size, mydriasis resulting from concomitant therapy with Timolol Maleate Ophthalmic Solution and epinephrine has been reported occasionally. Beta-adrenergic blocking agents: Patients who are receiving a beta-adrenergic blocking agent orally and Timolol Maleate Ophthalmic Solution should be observed for potential additive effects of beta-blockade, both systemic and on intraocular pressure. The concomitant use of two topical beta-adrenergic blocking agents is not recommended. Calcium antagonists: Caution should be used in the coadministration of beta-adrenergic blocking agents, such as Timolol Maleate Ophthalmic Solution, and oral or intravenous calcium antagonists because of possible atrioventricular conduction disturbances, left ventricular failure, and hypotension.

Storage Store at 15°C to 25°C (59°F to 77°F). Protect from freezing. Protect from light.