beta-blocker


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beta-blocker

or

beta-adrenergic blocking agent

(bā`tə ăd'rənûr`jĭk), drug that reduces the symptoms connected with hypertensionhypertension
or high blood pressure,
elevated blood pressure resulting from an increase in the amount of blood pumped by the heart or from increased resistance to the flow of blood through the small arterial blood vessels (arterioles).
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, cardiac arrhythmiasarrhythmia
, disturbance in the rate or rhythm of the heartbeat. Various arrhythmias can be symptoms of serious heart disorders; however, they are usually of no medical significance except in the presence of additional symptoms.
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, angina pectorisangina pectoris
, condition characterized by chest pain that occurs when the muscles of the heart receive an insufficient supply of oxygen. This results when the arteries that supply the heart muscle with oxygenated blood are narrowed by arteriosclerosis.
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, migrainemigraine
, headache characterized by recurrent attacks of severe pain, usually on one side of the head. It may be preceded by flashes or spots before the eyes or a ringing in the ears, and accompanied by double vision, nausea, vomiting, or dizziness.
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 headaches, and other disorders related to the sympathetic nervous systemnervous system,
network of specialized tissue that controls actions and reactions of the body and its adjustment to the environment. Virtually all members of the animal kingdom have at least a rudimentary nervous system.
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. Beta-blockers also are sometimes given after heart attacks to stabilize the heartbeat. Within the sympathetic nervous system, beta-adrenergic receptors are located mainly in the heart, lungs, kidneys, and blood vessels. Beta-blockers compete with the nerve-stimulating hormone epinephrineepinephrine
, hormone important to the body's metabolism, also known as adrenaline. Epinephrine, a catecholamine, together with norepinephrine, is secreted principally by the medulla of the adrenal gland.
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 for these receptor sites and thus interfere with the action of epinephrine, lowering blood pressure and heart rate, stopping arrhythmias, and preventing migraine headaches. Because it is also epinephrine that prepares the body for "fight or flight" in stressful or fearful situations, beta-blockers are sometimes used as antianxiety drugsantianxiety drug,
drug administered for the relief of anxiety. Although their action is not fully understood, most antianxiety medications appear to affect the action of neurotransmitters in the brain (see serotonin and norepinephrine).
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, especially for stage fright and the like. People taking a beta-blocker must avoid caffeine, alcohol, and salty foods, because the interaction of those substances and the drug can raise the heart rate and blood pressure. Propranolol (Inderal) is a commonly used beta-blocker.

beta-blocker

Medicine any of a class of drugs, such as propranolol, that inhibit the activity of the nerves that are stimulated by adrenaline; they therefore decrease the contraction and speed of the heart: used in the treatment of high blood pressure and angina pectoris
References in periodicals archive ?
In addition, beta-blockers have been shown to slow the progression of heart failure, improve its severity and reduce the risk of arrhythmias.
In experiments with a different mouse model of pancreatic cancer, the CUMC team demonstrated that treating mice with chemotherapy and nonselective beta-blockers, which are used to treat a variety of conditions, lived significantly longer than mice treated with chemotherapy alone.
APACHE-II scores and maximum HR<100/min were independent variables predicting ICU mortality in multivariate logistic regression analysis whereas usage of beta-blockers was not.
A 2013 network meta-analysis compared beta-blockers with placebo or standard treatment by analyzing 21 randomized trials with a total of 23,122 patients.
Other beta-blockers have a more general action and block shaking and sweating.
We calculated a priori that to observe a 50% increase in effective perioperative beta-blocker therapy in patients prescribed perioperative betablockers from 40% to >60% or a 50% decrease from 40% to <20%, we needed 260 patients in each cohort (type I error 0.
Beta-blockers are commonly used in the treatment of hypertension (high blood pressure) to help reduce the risk of stroke and cardiovascular disease.
In fact, after controlling for baseline depression, researchers found that beta-blocker users demonstrated significantly lower BDI scores 3 months post-MI than nonusers.
PITTSBURGH -- Beta-blockers may have a protective effect in patients with traumatic brain injury, significantly reducing mortality, based on a retrospective study of more than 2,000 patients.
The use of cardioselective beta-blockers can improve survival in "carefully selected" patients with chronic obstructive pulmonary disease (COPD) undergoing vascular surgery, according to a report in the first October issue of the American Journal of Respiratory and Critical Care Medicine.
Re-examining the efficacy of beta-blockers for the treatment of hypertension: a meta-analysis.
Do not suddenly stop taking the beta-blocker without telling your doctor, as that can be harmful.

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