Global Health
Beta-adrenergic blockers – how do they work?
Beta-blockers (β-blockers) affect the beta receptors of the sympathetic nervous system and are used to treat many acute and chronic diseases. There are three kinds of beta receptors: beta-1 (B1) are positioned in the guts and mediate cardiac function; beta-2 (B2) are positioned in various organs and cause leisure of smooth muscles; and beta-3 (B3) induce fat cell metabolism (Farzam and Jan, 2022). Beta blockers are classified as non-selective or beta-selective; non-selective drugs bind to each beta-1 and beta-2 receptors, while beta-1-selective drugs bind only to beta-1 receptors. Beta-3 receptors are currently of little clinical significance.
How do they work?
Catecholamines akin to epinephrine and noradrenaline stimulate B1 adrenergic receptors, causing a rise in heart rate, heart muscle contraction and blood pressure, and loosen up bronchial smooth muscles within the lungs. Beta-blockers prevent catecholamines from binding to those receptor sites, leading to a discount in heart rate, heart contraction, and blood pressure. This illustration shows the results of beta blockers on the guts, lungs and blood vessels.
Indications
Beta-blockers are indicated for the treatment of cardiac diseases akin to hypertension (HTN), angina pectoris, cardiac arrhythmias, hypertrophic cardiomyopathy, heart failure (HF), myocardial infarction (MI), tachycardia, and aortic dissection. Beta-blockers have also been used to forestall migraine, glaucoma, hyperthyroidism, portal hypertension, and muscle tremors (Farzam and Jan, 2022).
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| Not applicable | Beta-1 | HTN, premature ventricular beats | |
| Tenormin | Beta-1 | Angina, HTN, MI | |
| Not applicable | Beta-1 | HTN | |
| Not applicable | Beta-1 | HTN | |
| Not applicable | Non-selective | Glaucoma | |
| Core | Non-selective | Heart failure with reduced ejection fraction (HFwREF), left ventricular dysfunction after heart attack, hypertension | |
| Breviblok | Beta-1 | Atrial fibrillation/flutter (rate control), HTN, intraoperative and postoperative tachycardia, sinus tachycardia, SVT | |
| Not applicable | Non-selective | HTN | |
| Not applicable | Non-selective | Glaucoma | |
| Lopressor Toprol |
Beta-1 | Angina pectoris, HFwREF, HTN, MI | |
| Corgard | Non-selective | Angina pectoris, HTN | |
| Bystolski | Beta-1 | HTN | |
| Not applicable | Non-selective | HTN | |
| Hemangeol Inderal InnoPran |
Non-selective | Angina pectoris, atrial fibrillation/flutter [rate control]cardiac arrhythmias, essential tremor, arterial hypertension, hypertrophic cardiomyopathy, migraine prophylaxis, myocardial infarction, pheochromocytoma, proliferating infantile hemangioma, refractory tachyarrhythmias (during anesthesia), supraventricular arrhythmias, ventricular tachycardia | |
| Betapac Sorin Sotilize |
Non-selective | Atrial fibrillation/flutter [rate control]ventricular arrhythmias | |
| Not applicable | Non-selective | HTN, migraine prevention, heart attack | |
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Facts and comparisons. (2020, September 17). Beta-adrenergic blocking agents (beta-blockers) https://online.factsandcomparisons.com/lco/action/doc/retrieve/docid/fc_dfc/5545850
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Farzam, K. and Jan, A. (2022). Beta-blockers. StatPearls. https://www.ncbi.nlm.nih.gov/books/NBK532906/