betaxolol

Absorption: Well absorbed after oral administration.

Distribution: Widely distributed.

Metabolism/Excretion: Mostly metabolized by the liver, 20% excreted unchanged by the kidneys.

Half-Life: 15–20 hr.

Time/Action Profile ⬆ ⬇

(antihypertensive effect)

ROUTE	ONSET	PEAK	DURATION
PO	3–4 hr	3–4 hr	24 hr

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Uncompensated HF;
Pulmonary edema;
Cardiogenic shock;
Bradycardia or heart block.

Use Cautiously in:

Renal or hepatic impairment;
Pulmonary disease (including asthma; beta₁ selectivity may be lost at higher doses); avoid use if possible;
Diabetes mellitus;
Thyrotoxicosis;
History of severe allergic reactions (intensity of reactions may be ↑);
Untreated pheochromocytoma (initiate only after alpha blocker therapy started);
OB: Safety not established; crosses the placenta and may cause fetal/neonatal bradycardia, hypotension, hypoglycemia, or respiratory depression;
Geri: sensitivity to beta-blockers; initial dose recommended.

Adv. Reactions/Side Effects ⬆ ⬇

CV: HF, BRADYCARDIA, hypotension, peripheral vasoconstriction, PULMONARY EDEMA

Derm: rashes

EENT: blurred vision, stuffy nose

Endo: hyperglycemia, hypoglycemia

GI: ↑liver enzymes, constipation, diarrhea, nausea, vomiting

GU: erectile dysfunction, ↓libido, urinary frequency

MS: arthralgia, back pain, joint pain

Neuro: fatigue, weakness, anxiety, depression, dizziness, drowsiness, insomnia, memory loss, mental status changes, nightmares

Resp: bronchospasm, wheezing

Misc: drug-induced lupus syndrome

Interactions ⬆ ⬇

Drug-drug:

General anesthetics, IV phenytoin, and verapamil may cause additive myocardial depression.
Additive bradycardia may occur with digoxin, verapamil, or diltiazem.
Additive hypotension may occur with other antihypertensives, acute ingestion of alcohol, or nitrates.
Concurrent use with amphetamines, cocaine, epinephrine, norepinephrine, phenylephrine, or pseudoephedrine may result in unopposed alpha-adrenergic stimulation (excessive hypertension, bradycardia).
Concurrent thyroid preparation administration may ↓ effectiveness.
May alter the effectiveness of insulin or oral hypoglycemic agents (dosage adjustments may be necessary).
May ↓ the effectiveness of theophylline.
May ↓ the beneficial beta₁-cardiovascular effects of dopamine ordobutamine.
Use cautiously within 14 days of MAO inhibitor therapy (may result in hypertension).

Route/Dosage ⬆ ⬇

PO (Adults ): 10 mg once daily, may be ↑ to 20 mg after 7 days; start with 5 mg in geriatric patients or patients with renal impairment.

Renal Impairment

PO (Adults ): Start with 5 mg once daily.

Availability ⬆ ⬇

(Generic available)

Tablets: 10 mg; 20 mg

Assessment ⬆ ⬇

Monitor BP, ECG, and pulse frequently during dose adjustment and periodically during therapy.
Monitor intake and output ratios and daily weights. Assess routinely for signs and symptoms of HF (dyspnea, rales/crackles, weight gain, peripheral edema, jugular venous distention).
Angina: Assess frequency and characteristics of angina periodically during therapy.

Lab Test Considerations:

May cause ↑ BUN, serum lipoprotein, potassium, triglyceride, and uric acid levels.
- May cause ↑ ANA titers.
- May cause ↑ blood glucose levels.

Toxicity and Overdose:

Monitor patients receiving beta blockers for signs of overdose (bradycardia, severe dizziness or fainting, severe drowsiness, dyspnea, bluish fingernails or palms, seizures). Notify health care professional immediately if these signs occur.
- Glucagon has been used to treat bradycardia and hypotension.

Implementation ⬆ ⬇

PO: Take apical pulse before administering. If <50 bpm or if arrhythmia occurs, withhold medication and notify health care professional.
- May be administered without regard to food.

Patient/Family Teaching ⬆ ⬇

Instruct patient to take medication as directed, at the same time each day, even if feeling well; do not skip or double up on missed doses. Take missed doses as soon as possible up to 4 hr before next dose. Abrupt withdrawal may precipitate life-threatening arrhythmias, hypertension, or myocardial ischemia.
Advise patient to make sure enough medication is available for weekends, holidays, and vacations. A written prescription may be kept in wallet in case of emergency.
Teach patient and family how to check pulse and BP. Instruct them to check pulse daily and BP biweekly and to report significant changes.
May cause drowsiness or dizziness. Caution patients to avoid driving or other activities that require alertness until response to the drug is known.
Advise patients to change positions slowly to minimize orthostatic hypotension.
Caution patient that this medication may increase sensitivity to cold.
Instruct patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to consult health care professional before taking any OTC medications, especially cold preparations, concurrently with this medication.
Patients with diabetes should closely monitor blood glucose, especially if weakness, malaise, irritability, or fatigue occurs. Betaxolol may mask some signs of hypoglycemia, but sweating and dizziness may occur.
Advise patient to notify health care professional if slow pulse, difficulty breathing, wheezing, cold hands and feet, dizziness, confusion, depression, rash, fever, sore throat, unusual bleeding, or bruising occurs.
Instruct patient to inform health care professional of medication regimen before treatment or surgery.
Advise patient to carry identification describing disease process and medication regimen at all times.
Hypertension: Reinforce the need to continue additional therapies for hypertension (weight loss, sodium restriction, stress reduction, regular exercise, moderation of alcohol consumption, and smoking cessation). Medication controls but does not cure hypertension.

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇

Action ⬆ ⬇

Pharmacokinetics ⬆ ⬇