Timolol Hemihydrate 0.25%, 0.5% · ophthalmic solution
Antiglaucoma
Betimol ® is indicated in the treatment of elevated intraocular pressure in patients with ocular hypertension or open-angle glaucoma.
Contraindications
Betimol ® is contraindicated in patients with overt heart failure, cardiogenic shock, sinus bradycardia, second- or third-degree atrioventricular block, bronchial asthma or history of bronchial asthma, or severe chronic obstructive pulmonary disease, or hypersensitivity to any component of this product.
0.25%, 5 mL, 0.5%, 15 mL
Timolol is a non-selective beta-adrenergic antagonist. It blocks both beta 1 -and beta 2 -adrenergic receptors.
Betimol® Ophthalmic Solution is available in concentrations of 0.25% and 0.5%. The usual starting dose is one drop of 0.25% Betimol® 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.
Warnings & Precautions
- Cardiac Failure: Sympathetic stimulation may be essential for support of the circulation in individuals with diminished myocardial contractility, and its inhibition by beta-adrenergic receptor blockade may precipitate more severe cardiac failure.
- Obstructive Pulmonary Disease: Patients with chronic obstructive pulmonary disease (e.g. chronic bronchitis, emphysema) of mild or moderate severity, bronchospastic disease, or a history of bronchospastic disease (other than bronchial asthma or a history of bronchial asthma which are contraindications) should in general not receive beta-blocking agents.
- Major Surgery: The necessity or desirability of withdrawal of beta-adrenergic blocking agents prior to a major surgery is controversial. Beta-adrenergic receptor blockade impairs the ability of the heart to respond to beta-adrenergically mediated reflex stimuli.
Common Side Effects
The most frequently reported ocular event in clinical trials was burning/stinging on instillation and was comparable between Betimol ® and timolol maleate (approximately one in eight patients).
Pregnancy: Category C Teratogenicity of timolol (as the maleate) after oral administration was studied in mice and rabbits. No fetal malformations were reported in mice or rabbits at a daily oral dose of 50 mg/kg (7,000 times the systemic exposure following the maximum recommended human ophthalmic dose).
Lactation: Because of the potential for serious adverse reactions in nursing infants from timolol, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.
Safety and efficacy in pediatric patients have not been established.