| Revision as of 12:31, 23 February 2005 edit203.202.23.100 (talk) drug names← Previous edit | Revision as of 12:36, 23 February 2005 edit undo203.202.23.100 (talk)No edit summaryNext edit → | ||
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| Drugs that block beta 2 receptors generally have a relaxing effect and are prescribed for ], ], ] and ], among others. Many beta blockers affect both type 1 and type 2 receptors; these are termed ''non-selective'' blockers. | Drugs that block beta 2 receptors generally have a relaxing effect and are prescribed for ], ], ] and ], 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 ] or any reactive airway disease. Doing so can precipitate ]. | Non-selective beta blockers should not be used in patients with ] or any reactive airway disease. Doing so can precipitate ] by blocking the beta 2 mediated relaxation of the bronchiole muscles. | ||
| Since they lower heart rate, beta blockers have been ] by some ] ] to provide more aiming time between ]s. | Since they lower heart rate, beta blockers have been ] by some ] ] to provide more aiming time between ]s. | ||
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| Some ] use beta blockers to avoid ] and tremor during ]s and ]s. | Some ] use beta blockers to avoid ] and tremor during ]s and ]s. | ||
| Commonly used beta blockers include , , and the very short acting . | |||
| ==External links== | ==External links== | ||
Revision as of 12:36, 23 February 2005
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 syndrome, 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 asthma or any reactive airway disease. Doing so can precipitate bronchospasm by blocking the beta 2 mediated relaxation of the bronchiole muscles.
Since they lower heart rate, beta blockers have been abused by some Olympic marksmen to provide more aiming time between heartbeats.
Some musicians use beta blockers to avoid stage fright and tremor during auditions and performances.
External links
| Beta blockers (C07) | |
|---|---|
| β, non-selective | |
| β1-selective | |
| β2-selective | |
| α1- + β-selective | |
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