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| '''Beta blockers''' or '''beta-adrenergic blocking agents''' are |
'''Beta blockers''' or '''beta-adrenergic blocking agents''' are a class of ] used to treat a variety of cardiovascular conditions and some other diseases. | ||
| Beta blockers block the action of ] and ] on the β-]s in the body (primarily in the heart, peripheral blood vessels, bronchi, pancreas, and liver). The hormones and neurotransmitters stimulate the ] by acting on these receptors. | |||
| ⚫ | There are two types of beta receptors: beta |
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| ⚫ | There are two types of beta receptors: β<sub>1</sub>-receptors located mainly in the heart, and β<sub>2</sub>-receptors located all over the body, but mainly in the ]s, ]s and ]s. | ||
| ⚫ | |||
| ⚫ | Activition of β<sub>1</sub>-receptors by epinephrine increases the heart rate and the ], and the heart consumes more ]. 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 often prescribed after ]. In addition, beta blockers prevent the release of ], 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 ], ] and ], among others. Many beta blockers affect both type 1 and type 2 receptors. | ||
| ⚫ | 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 block the effects of Beta-2 agonists, such as ]. | Non-selective beta blockers should not be used in patients with ] or any reactive airway disease. Doing so can block the effects of Beta-2 agonists, such as ]. | ||
Revision as of 05:07, 15 September 2004
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 often prescribed after heart attacks. 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 block the effects of Beta-2 agonists, such as salbutamol.
| Beta blockers (C07) | |
|---|---|
| β, non-selective | |
| β1-selective | |
| β2-selective | |
| α1- + β-selective | |
| |