Beta blocker
class of medications that are particularly used to manage cardiac arrhythmias, and to protect the heart from a second heart attack after a first heart attack
Beta blockers, also spelled β-blockers and also sometimes known as β-adrenergic receptor antagonists, are a class of medications predominantly used to manage abnormal heart rhythms (arrhythmia) and to protect the heart from a second heart attack after the first one (secondary prevention). They are also used widely to treat high blood pressure, though they are no longer the first choice for initial treatment of most people. They can also be used to treat anxiety – a notable example being the situational use of propranolol to help dampen the physical symptoms of performance anxiety.
Beta blockers are competitive antagonists that block the receptor sites for the endogenous catecholamines epinephrine (adrenaline) and norepinephrine (noradrenaline) on adrenergic beta receptors, of the sympathetic nervous system, which mediates the fight-or-flight response.
β-adrenergic receptors are found on cells of the heart muscles, smooth muscles, airways, arteries, kidneys, and other tissues that are part of the sympathetic nervous system and lead to stress responses, especially when they are stimulated by epinephrine (adrenaline). Beta blockers interfere with the binding to the receptor of epinephrine and other stress hormones and thereby weaken the effects of stress hormones.
Some beta blockers block activation of all types of β-adrenergic receptors and others are selective for one of the three known types of beta receptors, designated β1, β2, and β3 receptors. β1-Adrenergic receptors are located mainly in the heart and in the kidneys. β2-Adrenergic receptors are located mainly in the lungs, gastrointestinal tract, liver, uterus, vascular smooth muscle, and skeletal muscle. β3-Adrenergic receptors are located in fat cells.
The public source identifies “Beta blocker” as class of medications that are particularly used to manage cardiac arrhythmias, and to protect the heart from a second heart attack after a first heart attack. This brief keeps that definition visible, then builds a research path around Beta, blocker and class.
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This entry incorporates text from “Beta blocker” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.