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Betimol®

GoodRx

Timolol Hemihydrate 0.25%, 0.5% · ophthalmic solution

Antiglaucoma

Indication
Betimol ® is indicated in the treatment of elevated intraocular pressure in patients with ocular hypertension or open-angle glaucoma.
Contraindications
  • Overt heart failure
  • Cardiogenic shock
  • Sinus bradycardia
  • Second- or third-degree atrioventricular block
  • Bronchial asthma or history of bronchial asthma
  • Severe chronic obstructive pulmonary disease
  • Hypersensitivity to any component of this product
Available Forms
0.25%: 5 mL fill in a 5 cc container 0.5%: 5 mL fill in a 5 cc container, 15 mL fill in a 15 cc container
Mechanism of Action
Timolol is a non-selective beta-adrenergic antagonist. It blocks both beta 1 -and beta 2 -adrenergic receptors.
Dosage
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. 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). Because of diurnal variations in intraocular pressure, satisfactory response to the once-a-day dose is best determined by measuring the intraocular pressure at different times during the day. Since in some patients the pressure-lowering response to Betimol® may require a few weeks to stabilize, evaluation should include a determination of intraocular pressure after approximately 4 weeks of treatment with Betimol®. Dosages above one drop of 0.5% Betimol® twice a day generally have not been shown to produce further reduction in intraocular pressure.
Warnings & Precautions
  • Severe respiratory and cardiac reactions: Betimol ® is absorbed systemically, and the same adverse reactions found with systemic administration of beta-adrenergic blocking agents may occur with topical administration. Severe respiratory 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 topical administration of beta-adrenergic blocking agents.
  • 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. In patients without a history of cardiac failure, continued depression of the myocardium with beta-blocking agents over a period of time can, in some cases, lead to cardiac failure. Betimol ® should be discontinued at the first sign or symptom of 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: Beta-blocker withdrawal before major surgery is controversial. Blockade impairs the heart's response to beta-adrenergically mediated reflex stimuli and may augment the risk of general anesthesia. Some patients have had protracted severe hypotension during anesthesia, and difficulty in restarting and maintaining the heartbeat has been reported. Gradual withdrawal is recommended before elective surgery; if necessary during surgery, sufficient doses of beta-adrenergic agonists may reverse the effects.
  • Diabetes Mellitus: Beta-adrenergic blocking agents should be administered with caution in patients subject to spontaneous hypoglycemia or to diabetic patients (especially those with labile diabetes) who are receiving insulin or oral hypoglycemic agents. Beta-adrenergic receptor blocking agents may mask the signs and symptoms of acute hypoglycemia.
  • Thyrotoxicosis: Beta-adrenergic blocking agents may mask certain clinical signs (e.g. tachycardia) of hyperthyroidism. Patients suspected of developing thyrotoxicosis should be managed carefully to avoid abrupt withdrawal of beta-adrenergic blocking agents which might precipitate a thyroid storm.
  • Cerebrovascular Insufficiency: Because of the potential effects of beta-adrenergic blocking agents relative to blood pressure and pulse, these agents should be used with caution in patients with cerebrovascular insufficiency. If signs or symptoms suggesting reduced cerebral blood flow develop following initiation of therapy with Betimol ®, alternative therapy should be considered.
  • Muscle Weakness: Beta-adrenergic blockade has been reported to potentiate muscle weakness consistent with certain myasthenic symptoms (e.g. diplopia, ptosis, and generalized weakness). Beta-adrenergic blocking agents have been reported rarely to increase muscle weakness in some patients with myasthenia gravis or myasthenic symptoms.
  • Angle-Closure Glaucoma: In angle-closure glaucoma, the goal of the treatment is to reopen the angle. This requires constricting the pupil. Betimol ® has no effect on the pupil. Therefore, if timolol is used in angle-closure glaucoma, it should always be combined with a miotic and not used alone.
  • Anaphylaxis: While taking beta-blockers, patients with a history of atopy or a history of severe anaphylactic reactions to a variety of allergens may be more reactive to repeated accidental, diagnostic, or therapeutic challenge with such allergens. Such patients may be unresponsive to the usual doses of epinephrine used to treat anaphylactic reactions.
  • Contact Lens Use: The preservative benzalkonium chloride may be absorbed by soft contact lenses. Patients who wear soft contact lenses should wait 5 minutes after instilling Betimol ® before they insert their lenses.
  • 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.
  • Additive beta-blockade: Patients who are receiving a beta-adrenergic blocking agent orally and Betimol ® should be observed for a potential additive effect either on the intraocular pressure or on the known systemic effects of beta-blockade. Patients should not usually receive two topical ophthalmic beta-adrenergic blocking agents concurrently.
  • Hypotension and marked bradycardia: Close observation of the patient is recommended when a beta-blocker is administered to patients receiving catecholamine-depleting drugs such as reserpine, because of possible additive effects and the production of hypotension and/or marked bradycardia, which may produce vertigo, syncope, or postural hypotension.
  • Atrioventricular conduction disturbances: Caution should be used in the co-administration of beta-adrenergic blocking agents and oral or intravenous calcium antagonists, because of possible atrioventricular conduction disturbances, left ventricular failure, and hypotension. In patients with impaired cardiac function, co-administration should be avoided. Digitalis with calcium antagonists may have additive effects in prolonging atrioventricular conduction time.
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). Adverse events associated with Betimol ® in frequencies of more than 5% in two controlled, double-masked clinical studies were dry eyes, itching, foreign body sensation, discomfort in the eye, eyelid erythema, conjunctival injection, and headache.
Pregnancy & Lactation
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). There are no adequate and well-controlled studies in pregnant women. Betimol ® should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
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.
Pediatric Use
Safety and efficacy in pediatric patients have not been established.