Betaxon

Uses

Betaxon ophthalmic solution has been shown to be effective in lowering intraocular pressure and is used for the treatment of ocular hypertension and chronic open-angle glaucoma. May be used alone or in combination with other intraocular pressure lowering medication.

Betaxon is also used to associated treatment for these conditions: High Blood Pressure (Hypertension), Increased Intra Ocular Pressure (IOP)

How Betaxon works

Betaxon selectively blocks catecholamine stimulation of beta(1)-adrenergic receptors in the heart and vascular smooth muscle. This results in a reduction of heart rate, cardiac output, systolic and diastolic blood pressure, and possibly reflex orthostatic hypotension. Betaxon can also competitively block beta(2)-adrenergic responses in the bronchial and vascular smooth muscles, causing bronchospasm.

Dosage

Betaxon dosage

The usual dose is 1 drop of Betaxon eye drops in the affected eye(s) twice daily. In some patients, the intraocular pressure lowering response may require a few weeks to stabilize. Clinical follow-up should include a determination of the intraocular pressure during the first month of treatment. Thereafter, intraocular pressure should be determined on an individual basis at the judgment of the physician.

Side Effects

Discomfort of short duration, occasional tearing has been reported. Rare instances of decreased corneal sensitivity, erythema, itching sensation, corneal punctuate staining, keratitis, edema and photophobia have been reported.

Toxicity

Oral LD₅₀s are 350 to 400 mg betaxolol/kg in mice and 860 to 980 mg/kg in rats. Predicted symptoms of overdose include bradycardia, congestive heart failure, hypotension, bronchospasm, and hypoglycemia.

Precaution

Use cautiously in diabetes mellitus, thyrotoxicosis, muscle weakness, major surgery, pulmonary, risk from anaphylactic reaction, carcinogenesis, mutagenesis, impairment of fertility.

Interaction

Betaxon is an adrenergic blocking agent; therefore, caution should be exercised in patients using concomitant adrenergic psychotropic drug. In patients with angle-closure glaucoma, Betaxon ophthalmic solution should be used with a miotic and not alone.

Food Interaction

• No food interactions are expected.

Betaxon Alcohol interaction

[Moderate]

Many psychotherapeutic and CNS-active agents (e.g., anxiolytics, sedatives, hypnotics, antidepressants, antipsychotics, opioids, alcohol, muscle relaxants) exhibit hypotensive effects, especially during initiation of therapy and dose escalation.

Coadministration with antihypertensives and other hypotensive agents, in particular vasodilators and alpha-blockers, may result in additive effects on blood pressure and orthostasis.

Caution and close monitoring for development of hypotension is advised during coadministration of these agents.

Some authorities recommend avoiding alcohol in patients receiving vasodilating antihypertensive drugs.

Patients should be advised to avoid rising abruptly from a sitting or recumbent position and to notify their physician if they experience dizziness, lightheadedness, syncope, orthostasis, or tachycardia.

Betaxon Cholesterol interaction

[Moderate] Beta-adrenergic receptor blocking agents (aka beta-blockers) may alter serum lipid profiles.

Increases in serum VLDL and LDL cholesterol and triglycerides, as well as decreases in HDL cholesterol, have been reported with some beta-blockers.

Patients with preexisting hyperlipidemia may require closer monitoring during beta-blocker therapy, and adjustments made accordingly in their lipid-lowering regimen.

Betaxon multivitamins interaction

[Moderate] ADJUST DOSING INTERVAL: Concurrent administration with calcium salts may decrease the oral bioavailability of atenolol and possibly other beta-blockers.

The exact mechanism of interaction is unknown.

In six healthy subjects, calcium 500 mg (as lactate, carbonate, and gluconate) reduced the mean peak plasma concentration (Cmax) and area under the concentration-time curve (AUC) of atenolol (100 mg) by 51% and 32%, respectively.

The elimination half-life increased by 44%.

Twelve hours after the combination, beta-blocking activity (as indicated by inhibition of exercise tachycardia) was reduced compared to that with atenolol alone.

However, during a 4-week treatment in six hypertensive patients, there was no difference in blood pressure values between treatments.

The investigators suggest that prolongation of the elimination half-life induced by calcium coadministration may have led to atenolol cumulation during long-term dosing, which compensated for the reduced bioavailability.

It may help to separate the administration times of beta-blockers and calcium products by at least 2 hours.

Patients should be monitored for potentially diminished beta-blocking effects following the addition of calcium therapy.

Betaxon Drug Interaction

Moderate: lithium, lithiumUnknown: arginine, arginine, levocarnitine, levocarnitine, lamotrigine, lamotrigine, fluoxetine, fluoxetine, valproic acid, valproic acid, cyanocobalamin, cyanocobalamin, pyridoxine, pyridoxine, cholecalciferol, cholecalciferol, phytonadione, phytonadione

Betaxon Disease Interaction

Major: bradyarrhythmia/AV block, cardiogenic shock/hypotension, CHF, diabetes, hemodialysis, hypersensitivity, ischemic heart disease, PVD, renal dysfunctionModerate: cerebrovascular insufficiency, glaucoma, hyperlipidemia, hyperthyroidism, myasthenia gravis, pheochromocytoma, psoriasis, tachycardia, asthma/COPD

Elimination Route

Absorption of an oral dose is complete. There is a small and consistent first-pass effect resulting in an absolute bioavailability of 89% ± 5% that is unaffected by the concomitant ingestion of food or alcohol.

Half Life

14-22 hours

Pregnancy & Breastfeeding use

Pregnancy: There are no adequate and well controlled studies in pregnant women. Betaxon Hydrochloride Ophthalmic Solution should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Lactation: It is not known whether betaxolol HCl is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when Betaxon Hydrochloride Ophthalmic Solution is administered to nursing women.

Contraindication

Hypersensitivity to any component of this product. Betaxon should not be used in patients with sinus bradycardia, atrioventricular block greater than first degree, cardiogenic shock, or patients with a history of overt cardiac failure.

Special Warning

Pediatric Use: Safety and effectiveness in pediatric patients have not been established.

Geriatric Use: No overall differences in safety or effectiveness have been observed between elderly and younger patients.

Acute Overdose

No information is available on overdosage. A topical overdosage of Betaxon ophthalmic solution may be flushed from the eye(s) with warm tap water.

Storage Condition

Store in a cool and dry place, away from light. Keep out of reach of children. Store below 30°C

Innovators Monograph

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