Pharmacologic Profile

General Use

Management of hypertension, angina pectoris, tachyarrhythmias, migraine headache (prophylaxis), MI, glaucoma (ophthalmic use), heart failure (HF) (bisoprolol, carvedilol, and sustained-release metoprolol only) and hyperthyroidism (management of symptoms only).

General Action and Information

Beta blockers compete with adrenergic (sympathetic) neurotransmitters (epinephrine and norepinephrine) for adrenergic receptor sites. Beta₁-adrenergic receptor sites are located chiefly in the heart where stimulation results in increased heart rate and myocardial contractility. Beta₂-adrenergic receptors are found mainly in bronchial and vascular smooth muscle and the uterus. Stimulation of beta₂-adrenergic receptors produces vasodilation, bronchodilation, and uterine relaxation. Beta blockers may be relatively selective for beta₁-adrenergic receptors (acebutolol, atenolol, betaxolol, bisoprolol, esmolol, and metoprolol) or nonselective (carvedilol, labetalol, nadolol, pindolol, propranolol, and timolol) blocking both beta₁- and beta₂-adrenergic receptors. Carvedilol and labetalol have additional alpha-adrenergic blocking properties. Ophthalmic beta blockers ↓ production of aqueous humor.

Contraindications

Decompensated HF, acute bronchospasm, some forms of valvular heart disease, bradyarrhythmias, and heart block.

Precautions

Use cautiously in pregnant and lactating women (may cause fetal bradycardia and hypoglycemia). Use cautiously in any form of lung disease. Use with caution in patients with diabetes or severe liver disease. Beta blockers should not be abruptly discontinued in patients with cardiovascular disease.

Interactions

May cause additive myocardial depression and bradycardia when used with other agents having these effects (digoxin, diltiazem, verapamil, clonidine, and ivabradine). May antagonize the therapeutic effects of bronchodilators. May alter the requirements for insulin or hypoglycemic agents in patients with diabetes. Cimetidine may ↓ the metabolism and ↑ the effects of some beta blockers.

Nursing Implications

Assessment

• Monitor BP and pulse frequently during dosage adjustment and periodically throughout therapy.
• Monitor intake and output ratios and daily weight. Assess patient routinely for signs and symptoms of HF (dyspnea, rales/crackles, weight gain, peripheral edema, jugular venous distention).
• Assess frequency and severity of episodes of chest pain periodically throughout therapy.
• Assess frequency and severity of migraine headaches periodically throughout therapy.

Potential Nursing Diagnoses

• Ineffective tissue perfusion (Indications)
• Deficient knowledge related to disease processes and medication regimen (Patient/Family Teaching)
• Noncompliance (Patient/Family Teaching)

Implementation

• Take apical pulse prior to administering. If heart rate is <50 bpm or if arrhythmias occur, hold medication and notify health care professional.

Patient/Family Teaching

• Instruct patient to continue taking medication, even if feeling well. Abrupt withdrawal may cause life-threatening arrhythmias, hypertension, or myocardial ischemia. Medication controls, but does not cure, hypertension.
• Encourage patient to comply with additional interventions for hypertension (weight reduction, low-sodium diet, regular exercise, smoking cessation, moderation of alcohol consumption, and stress management).
• Instruct patient and family on proper technique for monitoring BP. Advise them to check BP weekly and report significant changes to health care professional.
• Caution patient to make position changes slowly to minimize orthostatic hypotension. Advise patient that exercising or hot weather may enhance hypotensive effects.
• Advise patient to consult health care professional before taking any OTC medications or herbal/alternative therapies, especially cold remedies.
• Patients with diabetes should monitor blood glucose closely, especially if weakness, malaise, irritability, or fatigue occurs.
• Advise patient to advise health care professional of medication regimen prior to treatment or surgery.
• Advise patient to carry identification describing disease process and medication regimen at all times.
• Emphasize the importance of follow-up exams to monitor progress.
• Instruct patient in correct technique for administration of ophthalmic preparations.

Evaluation/Desired Outcomes

• Decrease in BP.
• Decrease in frequency and severity of anginal attacks.
• Control of arrhythmias.
• Prevention of myocardial reinfarction.
• Prevention of migraine headaches.
• Decrease in tremors.
• Lowering of intraocular pressure.