Betaxolol Hydrochloride Ophthalmic

Topically applied beta-adrenergic blocking agents may be 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 with topical application of beta-adrenergic blocking agents.

Betaxolol Hydrochloride Ophthalmic Solution has been shown to have a minor effect on heart rate and blood pressure in clinical studies. Caution should be used in treating patients with a history of cardiac failure or heat block. Treatment with Betaxolol Hydrochloride Ophthalmic Solution (betaxolol hydrochloride) should be discontinued at the first signs of cardiac failure.

No information is available on overdosage of humans. The oral LD50 of the drug ranged from 350-920 mg/kg in mice and 860-1050 mg/kg in rats. The symptoms which might be expected with an overdose of a systemically administered beta-1-adrenergic receptor blocker agent are bradycardia, hypotension and acute cardiac failure. A topical overdose of Betaxolol Hydrochloride Ophthalmic Solution may be flushed from the eye(s) with warm tap water.

Betaxolol Hydrochloride HCl, a cardioselective (beta-1-adrenergic) receptor blocking agent, does not have significant membrane-stabilizing (local anesthetic) activity and is devoid of intrinsic sympathomimetic action. Orally administered beta-adrenergic blocking agents reduce cardiac output in healthy subjects and patients with heart disease. In patients with severe impairment of myocardial function, beta-adrenergic receptor antagonists may inhibit the sympathetic stimulatory effect necessary to maintain adequate cardiac function.

When instilled in the eye, Betaxolol Hydrochloride Ophthalmic Solution has the action of reducing elevated as well as normal intraocular pressure, whether or not accompanied by glaucoma. Ophthalmic betaxolol has minimal effect on pulmonary and cardiovascular parameters.

Ophthalmic betaxolol (one drop in each eye) was compared to timolol and placebo in a three-way crossover study challenging nine patients with reactive airway disease who were selected on the basis of having at least a 15% reduction in the forced expiratory volume in one second (FEV1) after administration of ophthalmic timolol. Betaxolol HCl had no significant effect on pulmonary function as measured by FEV1. Forced Vital Capacity (FVC) and FEV1/VC. Additionally, the action of isoproterenol, a beta stimulant, administered at the end of the study was not inhibited by ophthalmic betaxolol. In contrast, ophthalmic timolol significantly decreased these pulmonary functions.

1Schoene, R. B. et al., Am. J. Ophthal. 97:86, 1984.
aTwice the clinical concentration.
bInhaled at 240 minutes; measurement at 270 minutes.
*Timolol statistically different from betaxolol and placebo (p < 0.05).

No evidence of cardiovascular beta-adrenergic blockade during exercise was observed with betaxolol in a double-masked, three-way crossover study in 24 normal subjects comparing ophthalmic betaxolol, timolol and placebo for effect on blood pressure and heart rate. Mean arterial blood pressure was not affected by any treatment; however, ophthalmic timolol produced a significant decrease in the mean heart rate.

1Atkins, J. M. et al., AM. J. Oph. 99:173-175, Feb., 1985.
aTwice the clinical concentration.
*Mean pulse rate significantly lower for timolol than betaxolol or placebo (p < 0.05).

CLINICAL STUDIES

Optic nerve head damage and visual field loss are the result of a sustained elevated intraocular pressure and poor ocular perfusion. Betaxolol Hydrochloride Ophthalmic Solution (betaxolol hydrochloride) has the action of reducing elevated as well as normal intraocular pressure, and 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 Betaxolol Hydrochloride Ophthalmic Solution (betaxolol hydrochloride) can 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. Clinical observation of glaucoma patients treated with Betaxolol Hydrochloride Ophthalmic Solution (betaxolol hydrochloride) for up to three years shows that the intraocular pressure lowering effect is well maintained.

Clinical studies show that topical Betaxolol Hydrochloride Ophthalmic Solution (betaxolol hydrochloride) reduces mean intraocular pressure 25% from baseline. In trials using 22 mmHg as a generally accepted index of intraocular pressure control, Betaxolol Hydrochloride Ophthalmic Solution (betaxolol hydrochloride) was effective in more than 94% of the population studied, of which 73% were treated with the beta blocker alone. In controlled, double-masked studies, the magnitude and duration of the ocular hypotensive effect of Betaxolol Hydrochloride Ophthalmic Solution (betaxolol hydrochloride) and ophthalmic timolol solution were clinically equivalent.

Betaxolol Hydrochloride Ophthalmic Solution (betaxolol hydrochloride) has also been used successfully in glaucoma patients who have undergone a laser trabeculoplasty and have needed additional long-term ocular hypotensive therapy.

Betaxolol Hydrochloride Ophthalmic Solution (betaxolol hydrochloride) has been well tolerated in glaucoma patients wearing hard or soft contact lenses and in aphakic patients.

Betaxolol Hydrochloride Ophthalmic Solution (betaxolol hydrochloride) does not produce miosis or accommodative spasm which are frequently seen with miotic agents. The blurred vision and night blindness often associated with standard miotic therapy are not associated with Betaxolol Hydrochloride Ophthalmic Solution (betaxolol hydrochloride) . Thus, patients with central lenticular opacities avoid the visual impairment caused by a constricted pupil.

Do not use this medication if you are allergic to betaxolol, or if you have asthma, or severe chronic obstructive pulmonary disease (COPD), slow heartbeats, or a heart condition called "AV block."

Before using this medication, tell your doctor if you have breathing problems such as bronchitis or emphysema, a history of heart disease or congestive heart failure, diabetes, history of stroke, blood clot, or circulation problems, a thyroid disorder, or a muscle disorder such as myasthenia gravis.

Do not allow the dropper to touch any surface, including the eyes or hands. If the dropper becomes contaminated it could cause an infection in your eye, which can lead to vision loss or serious damage to the eye.

Betaxolol ophthalmic is sometimes given together with other eye medications. Do not use any other eye medication unless your doctor has prescribed it for you. If you use another eye medication, use it at least 10 minutes before or after using betaxolol ophthalmic. Do not use the medications at the same time.

Betaxolol ophthalmic can cause blurred vision. Be careful if you drive or do anything that requires you to be able to see clearly.

Do not use this medication while you are wearing contact lenses. Betaxolol ophthalmic may contain a preservative that can be absorbed by soft contact lenses. Wait at least 15 minutes after using betaxolol before putting your contact lenses in.

Betaxolol ophthalmic can cause blurred vision. Be careful if you drive or do anything that requires you to be able to see clearly.

Betaxolol ophthalmic is sometimes given together with other eye medications. Do not use any other eye medication unless your doctor has prescribed it for you. If you use another eye medication, use it at least 10 minutes before or after using betaxolol ophthalmic. Do not use the medications at the same time.

• Glaucoma