Pronunciation: BAY-TAX-oh-lahl HIGH-droe-KLOR-ide
Class: Beta-adrenergic blocking agent
- Solution 5.6 mg (equivalent to 5 mg base) per mL (0.5%)
- Suspension 2.8 mg (equivalent to 2.5 mg base) per mL (0.25%)
- Tablets 10 mg
- Tablets 20 mg
Blocks beta receptors, primarily affecting cardiovascular system (decreases heart rate, cardiac contractility, and BP) and lungs (promotes bronchospasm). Ophthalmic use reduces IOP, probably by reducing aqueous production.
Bioavailability is about 89%, C max is about 21.6% ng/mL (10 mg dose), and T max is about 3 h.
Approximately 50% protein bound.
Metabolized in liver to inactive metabolites.
The t ½ is 14 to 22 h. More than 80% is recovered in urine as betaxolol and metabolites; about 15% excreted as unchanged drug.
Within 30 min.
7 to 14 days.Ophthalmic
Special PopulationsRenal Function Impairment
In moderate to severe impairment, Cl is decreased significantly. In those undergoing dialysis, the t ½ and AUC are approximately doubled. Dosage adjustment required for those with severe renal function impairment and those undergoing dialysis.Hepatic Function Impairment
The t ½ may be prolonged but Cl is unchanged. Dosage adjustments not needed.Elderly
Elimination may be decreased. Dosage adjustment required.
Indications and Usage
Lowering IOP; ocular hypertension; chronic open-angle glaucoma.
Hypersensitivity to beta-blockers; sinus bradycardia; greater than first-degree heart block; CHF unless secondary to tachyarrhythmia treatable with beta-blockers; overt cardiac failure; cardiogenic shock.
Dosage and AdministrationHypertension
PO 10 to 20 mg/day.Elderly
PO Reduce initial dose to 5 mg/day.Glaucoma
Ophthalmic 1 to 2 drops twice daily in affected eye(s). Consider concomitant therapy if IOP is not at satisfactory level.
Store oral form in cool location. Store ophthalmic form at room temperature. Do not freeze.
May enhance or reverse antihypertensive effect; potentially life-threatening situations may occur, especially on withdrawal.NSAIDs
Some agents may impair antihypertensive effect.Prazosin
May increase postural hypotension.Verapamil
May increase effects of both drugs.
Laboratory Test Interactions
None well documented.
Hypotension; bradycardia; CHF; cold extremities; second- or third-degree heart block; arrhythmias; syncope.
Insomnia; fatigue; dizziness; depression; lethargy; drowsiness; forgetfulness; headache.
Rash; hives; alopecia.
Dry eyes; blurred vision; tinnitus; slurred speech; dry mouth; sore throat. Ophthalmic use may cause eye discomfort or stinging; tearing; keratitis; blepharoptosis; visual disturbances; diplopia; ptosis.
Nausea; vomiting; diarrhea; constipation.
Impotence; painful, difficult, or frequent urination.
Agranulocytosis; thrombocytopenic purpura.
Acidosis; diabetes; hypercholesterolemia; hyperlipidemia; increased LDH; hypokalemia.
Bronchospasm; dyspnea; wheezing.
Weight changes; fever; facial swelling; muscle weakness. Ophthalmic betaxolol may produce the same adverse drug reactions seen with systemic use; antinuclear antibodies may develop.
Category C .
Excreted in breast milk.
Safety and efficacy not established.
Dosage reduction may be necessary.
Use with caution.
Use with caution.
Deaths have occurred with anaphylactic reactions to beta-blockers; aggressive therapy may be required.
To effectively reduce elevated IOP in angle-closure glaucoma, use with miotic agent.
Cessation of therapy
Gradually withdraw over about 2 wk. Carefully observe patients and allow minimal physical activity.
Cautiously administer in patients whose CHF is controlled by digitalis and diuretics.
May mask symptoms of hypoglycemia (eg, tachycardia, BP changes). May potentiate insulin-induced hypoglycemia.
Nonallergic bronchospastic disease (eg, chronic bronchitis, emphysema)
In general, beta-blockers are not given to patients with bronchospastic diseases.
Peripheral vascular disease
May precipitate or aggravate symptoms of arterial insufficiency.
Ophthalmic betaxolol may produce same adverse reactions seen with systemic use because of absorption.
May mask clinical signs (eg, tachycardia) of developing or continuing hyperthyroidism. Abrupt withdrawal may exacerbate symptoms of hyperthyroidism, including thyroid storm.
Bradycardia, CHF, hypotension, bronchospasm, hypoglycemia.
- Explain that full effectiveness of drug may not occur for up to 1 to 2 wk after initiation of therapy and that dosage will be tapered slowly before stopping to prevent adverse effects (eg, hypotension, tachycardia, anxiety, angina, MI).
- Teach patient how to monitor pulse before taking oral medication, and advise to contact health care provider if pulse remains less than 50 bpm.
- Inform patients with diabetes to monitor blood glucose level closely.
- Advise patient that ophthalmic solution may cause initial burning or stinging when first instilled in eye.
- Instruct patient to inform health care provider of any scheduled surgery or dental work; dosage may need to be gradually tapered (and ophthalmic solution discontinued) before surgery or treatment.
- Explain that measurements of IOP will need to be performed on a regular basis to assess the therapeutic effect of the ophthalmic medication.
- Instruct patient to report the following symptoms to health care provider: dizziness, decreased pulse, shortness of breath, confusion, rash, or any unusual bleeding.
- Instruct patient not to take OTC medications (including diet aids, cold or nasal preparations [alpha-adrenergic stimulants]) without consulting health care provider.
- Advise patient that drug may cause drowsiness, and to use caution while driving or performing other tasks requiring mental alertness.
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