PHARMACOLOGICAL ACTION: Betaxolol HCl is a cardioselective (beta-1-adrenergic) receptor blocking agent.
When instilled in the eye, BETOPTIC reduces elevated as well as normal intraocular pressure.
The mechanism of ocular hypotensive action appears to be a reduction of aqueous production as demonstrated by tonography and aqueous fluorophotometry. The onset of action with BETOPTICcan generally be noted within 30 minutes and the maximal effect can usually be detected 2 hours after topical administration. A single dose provides a 12 hour reduction in intraocular pressure: BETOPTIC does not produce miosis or accommodative spasm.
During therapy with betaxolol, no negative effect on the blood supply to the optic nerve has been observed.
INDICATIONS: BETOPTIChas been shown to be effective in lowering intraocular pressure and is indicated in the treatment of:
Patients with chronic open-angle glaucoma.
Patients with elevated intraocular pressure (ocular hypertensive patients).
CONTRA-INDICATIONS: Hypersensitivity to any component of this product. BETOPTIC is contra-indicated in patients with sinus bradycardia greater than a first degree block, cardiogenic shock, or patients with cardiac failure unless or until signs of failure are controlled with appropriate medicine.
WARNINGS: Caution should be used in treating patients with a history of cardiac failure or heart block. Treatment with BETOPTIC should be discontinued at the first signs of cardiac failure. Ocular: In patients with angle-closure glaucoma, the immediate treatment objective is to re-open the angle by constriction of the pupil with a miotic agent. Betaxolol has no effect on the pupil; therefore, BETOPTIC should be used with a miotic to reduce elevated intraocular pressure in angle-closure glaucoma. The ability to drive and use machines is unlikely to be affected following the use of BETOPTIC. As the possibility of adverse effects on the corneal permeability and the danger of disruption of the corneal epithelium with prolonged or repeated usage of benzalkonium chloride preserved ophthalmological preparations cannot be excluded, regular ophthalmological examination is required. Caution should be exercised in the use of benzalkonium chloride preserved topical medication over an extended period in patients with extensive ocular surface disease.
DOSAGE AND DIRECTIONS FOR USE: The usual dose is one drop of BETOPTIC in the affected eye(s) twice daily.
In some patients, the intraocular pressure lowering response to BETOPTIC may require a few weeks to stabilize.
Clinical follow up should include a determination of the intraocular pressure during the first month of treatment with BETOPTIC. Thereafter, intraocular pressures should be determined on an individual basis at the judgement of the physician. When a patient is transferred from a single anti-glaucoma non beta-blocking agent continue the agent already used and add one drop of BETOPTIC in the affected eye(s) twice a day. On the following day, discontinue the previous anti-glaucoma agent completely and continue with BETOPTIC.
Because of diurnal variations of intraocular pressure in individual patients, satisfactory response to twice a day therapy is best determined by measuring intraocular pressure at different times during the day. Therapy should be individualised. If the intraocular pressure of the patient is not adequately controlled on this regimen, concomitant therapy with pilocarpine, other miotics, epinephrine or systemically administered carbonic anhydrase inhibitors can be instituted. When a patient is transferred from several concomitantly administered anti-glaucoma agents individualization is required. Adjustment should involve one agent at a time made at intervals of not less than one week. A recommended approach is to continue the agents being used and add one drop of BETOPTIC in the affected eye(s) twice a day. On the following day, discontinue one of the other anti-glaucoma agents. The remaining anti-glaucoma agents may be decreased or discontinued according to the patient's response to treatment.
SIDE EFFECTS AND SPECIAL PRECAUTIONS:
PRECAUTIONS: Patients who are receiving a beta-adrenergic blocking agent orally and BETOPTIC should be observed for a potential additive effect either on the intraocular pressure or on the known systemic effects of beta blockade. BETOPTIC should be used with caution in patients with diabetes or in patients with thyrotoxicosis. Pulmonary: Caution should be exercised in patients with bronchial asthma, chronic bronchitis and hypersensitive airways as bronchoconstriction may be aggravated by BETOPTIC. Drug interactions: Although BETOPTIC used alone has little or no effect on pupil size, mydriasis resulting from concomitant therapy with BETOPTIC and epinephrine has been reported.
Close observation of the patient is recommended when a beta-blocker is administered to patients receiving catecholamine-depleting drugs such as reserpine and various antiarrhythmic agents because of possible additive effects and the production of hypotension and/or bradycardia.
Caution should be exercised in patients using concomitant hypoglycaemic agents and phenothiazines. Diminished responsiveness to BETOPTIC following long-term therapy has been reported. Pregnancy: Safety in pregnancy has not been established. Nursing Mothers: It is not known whether BETOPTIC is excreted in human milk.
Caution should be exercised when BETOPTIC is administered to nursing women. Usage in Children: Clinical studies to establish the safety and efficacy in children have not been performed. Long-term use: The long-term safety of beta-blockers has not yet been established. SIDE-EFFECTS: The following adverse reactions following topical administration of BETOPTIC have been reported: Ocular: Discomfort upon instillation and tearing. Instances of decreased corneal sensitivity, erythema, itching sensation, corneal punctate staining, keratitis, anisocoria and photophobia. Systemic: Systemic reactions such as insomnia and depressive neurosis.
Other systemic side-effects which may occur with the oral use of beta-blockers are:
Congestive cardiac failure and marked bradycardia, exacerbation of peripheral vascular disease, or the development of Raynaud's phenomenon (due to unopposed arteriolar-alpha-sympatic activation), sexual impotence, hypoglycaemia, skeletal muscle weakness and gastro-intestinal disturbances. Severe peripheral vascular disease and even peripheral gangrene may be precipitated. Neuropsychiatric disorders ranging from vague fatigue and malaise, vivid dreams and nightmares to overt psychosis. Infants of mothers administered beta-blockers shortly before giving birth, or during labour may be born hypotonic, collapsed and hypoglycaemic.
Adverse reactions are more common in patients with renal decompensation.
KNOWN SYMPTOMS OF OVERDOSAGE AND PARTICULARS OF ITS TREATMENT: No information is available on overdosage in humans. The symptoms which might be expected with an overdose of a systemically administered beta-1-adrenergic receptor blocking agent are bradycardia, hypotension and acute cardiac failure. A topical overdose of BETOPTIC may be flushed from the eye(s) with warm tap water.
IDENTIFICATION: A clear, colourless to pale yellow aqueous solution.