Beta adrenergic blockers (ß-blockers) affect the beta receptors of the sympathetic nervous system and are used to treat a multitude of acute and chronic diseases. There are three types of beta receptors: beta-1 (B1) are located in the heart and mediate cardiac activity; beta-2 (B2) are located in various organs and induce smooth muscle relaxation; and beta-3 (B3) induce fat cell metabolism (Farzam & Jan, 2022). Beta blockers are classified as either non-selective or beta-1 selective; non-selective drugs bind to both beta-1 and beta-2 receptors while beta-1 selective drugs bind only to beta-1 receptors. Beta-3 receptors have little clinical relevance at this time.
How do they work?
Catecholamines such as epinephrine and norepinephrine stimulate the B1 adrenergic receptors causing an increase in heart rate, heart muscle contraction, and blood pressure, and relaxes the smooth muscles in the bronchial tubes in the lungs. Beta adrenergic blockers prevent catecholamines from binding to these receptor sites resulting in a decrease in heart rate, heart contraction, and blood pressure. This illustration shows the effects of beta-adrenergic blockers on the heart, lungs, and blood vessels.
Indications
Beta adrenergic blockers are indicated to treat heart diseases such as hypertension (HTN), angina pectoris, cardiac arrhythmias, hypertrophic cardiomyopathy, heart failure (HF), myocardial infarction (MI), tachycardia, and aortic dissection. Beta blockers have also been used for migraine headache prophylaxis, glaucoma, hyperthyroidism, portal hypertension, and muscle tremor (Farzam & Jan, 2022).
Beta-Adrenergic Blockers
(Facts and Comparisons, 2020) |
| Generic Name |
Brand Name |
Beta Receptor Site |
FDA Approved Indications |
| Acebutolol |
N/A |
Beta-1 |
HTN, ventricular premature beats |
| Atenolol |
Tenormin |
Beta-1 |
Angina pectoris, HTN, MI |
| Betaxolol |
N/A |
Beta-1 |
HTN |
| Bisoprolol |
N/A |
Beta-1 |
HTN |
| Carteolol |
N/A |
Non-selective |
Glaucoma |
| Carvedilol |
Coreg |
Non-selective |
Heart failure with reduced ejection fraction (HFwREF), left ventricular dysfunction following MI, HTN |
| Esmolol |
Brevibloc |
Beta-1 |
Atrial fibrillation/flutter (rate control), HTN, intraoperative and postoperative tachycardia, sinus tachycardia, SVT |
| Labetalol |
N/A |
Non-selective |
HTN |
| Levobunolol |
N/A |
Non-selective |
Glaucoma |
| Metoprolol |
Lopressor
Toprol |
Beta-1 |
Angina pectoris, HFwREF, HTN, MI |
| Nadolol |
Corgard |
Non-selective |
Angina pectoris, HTN |
| Nebivolol |
Bystolic |
Beta-1 |
HTN |
| Pindolol |
N/A |
Non-selective |
HTN |
| Propranolol |
Hemangeol
Inderal
InnoPran |
Non-selective |
Angina pectoris, atrial fibrillation/flutter [rate control], cardiac arrhythmias, essential tremor, HTN, hypertrophic cardiomyopathy, migraine prophylaxis, MI, pheochromocytoma, proliferating infantile hemangioma, resistant tachyarrhythmias (during anesthesia), supraventricular arrhythmias, ventricular tachycardia |
| Sotalol |
Betapace
Sorine
Sotylize |
Non-selective |
Atrial fibrillation/flutter [rate control], ventricular arrhythmias |
| Timolol |
N/A |
Non-selective |
HTN, migraine prophylaxis, MI |
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