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Beta blockers or beta-adrenergic blocking agents are a class of drugs used to treat a variety of cardiovascular conditions and some other diseases.Beta blockers block the action of epinephrine and norepinephrine on the β- adrenergic receptors in the body (primarily in the heart, peripheral blood vessels, bronchi, pancreas, and liver). The hormones and neurotransmitters stimulate the sympathetic nervous system by acting on these receptors.
There are two types of beta receptors: β1-receptors located mainly in the heart, and β2-receptors located all over the body, but mainly in the lungs, muscles and arterioles.
Activition of β1-receptors by epinephrine increases the heart rate and the blood pressure, and the heart consumes more oxygen. Drugs that block these receptors therefore have the reverse effect: they lower the heart rate and blood pressure and hence are used in conditions when the heart itself is deprived of oxygen. They are routinely prescribed in patients with ischemic heart disease. In addition, beta blockers prevent the release of renin, which is a hormone produced by the kidneys which leads to constriction of blood vessels.
Drugs that block beta 2 receptors generally have a relaxing effect and are prescribed for anxiety, migraine, esophageal varices and alcohol withdrawal syndromeAlcohol withdrawal syndrome can occur to an alcoholic (one who is addicted to alcohol) in reaction to the discontinued use of alcohol. Withdrawal symptoms can be quite extreme, and can even result in death. Alcohol triggers the release of the neurotransmi, among others. Many beta blockers affect both type 1 and type 2 receptors; these are termed non-selective blockers.
Non-selective beta blockers should not be used in patients with asthmaAsthma is an immunological disease which causes difficulty in breathing. It is a form of type I hypersensitivity in which the bronchioles in the lungs are narrowed by inflammation and spasm of the lining of the airway wall. A person with asthma may experi or any reactive airway disease. Doing so can precipitate bronchospasmDifficulty in breathing caused by a sudden constriction of the muscles in the wall of the bronchi. A feature of asthma, chronic bronchitis and anaphylaxis. The overactivity of the bronchus muscle is as a result of exposure to a stimulus (trigger) which un.
Since they lower heart rate, beta blockers have been abusedIn sports, doping is generally the use of performance-enhancing drugs, such as anabolic steroids or EPO, particularly those that are forbidden by the organizations that regulate competitions in a certain sport. Some doping substances, however, are permitt by some OlympicOlympic Flame from Olympia to the opening ceremony. The Olympic Games or Olympics are an international multi-sport event taking place every fourth year. Originally held in ancient Greece, they were revived by a French nobleman, Pierre Fredy, Baron de Coub marksmenA marksman (also designated marksman) is a profession which is mostly to be found in military context. He/she is trained to shoot precisely with a certain type of rifle. Some military doctrines use marksmen attached to an infantry squad. In that capacity to provide more aiming time between heartbeats.
Some musicians use beta blockers to avoid stage fright during auditions, and performances.
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Beta blockers
