calcium-channel blocker


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calcium-channel blocker,

any of a class of drugs used in treating 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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, 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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, and certain 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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. They prevent the calcium ions needed for muscle contraction from entering the cells of smooth and cardiac muscle. This causes blood vessel walls to relax and blood to flow more freely to the heart, lowering blood pressure and relieving anginal pain. Some calcium-channel blockers, such as Procardia (nifedipine), slow the electrical impulses that run through heart muscle, thus regulating arrhythmias. Cardizem (diltiazem) is a common calcium-channel blocker.
References in periodicals archive ?
6,7) The first analyzed 54 trials involving 17 agents and focused on digoxin calcium-channel blockers and beta-blockers.
The atrial fibrillation evidence also suggests that we need to place beta-blocker and non-dihydropyridine calcium-channel blockers (ie, verapamil and diltiazem) as first-line choices for rate-control therapy.
However, an unpublished meta-analysis is purported to show a higher risk of heart failure, heart attack, and major cardiovascular events with calcium-channel blockers compared with diuretics, [Beta]-blockers, clonidine, or ACE inhibitors.
After adjusting for numerous other risk factors, such as smoking, alcohol use, and age, the researchers concluded that people taking calcium-channel blockers face a 72 percent greater risk of developing cancer than those not taking these drugs.
24 Lancet that other research has shown that calcium-channel blockers may interfere with mechanisms that limit cancer cell growth.
Medications for treating high blood pressure, called antihypertensives, are the most commonly prescribed drugs in the United States with an estimated 678 million prescriptions filled in 2010, including 98 million prescriptions for calcium-channel blockers, the researchers said.
This is not the first time that the spectre of a link between calcium-channel blockers and breast cancer risk has arisen," said Dr.
Ganciclovir had a long-term effect on patients who weren't getting drugs called calcium-channel blockers.
Two new studies of nifedipine, a drug commonly prescribed for high blood pressure and heart disease, have generated fierce controversy over the safety of calcium-channel blockers, the class of compounds to which nifedipine belongs.
These results, Furberg adds, make him question the safety of all calcium-channel blockers, particularly the newer, long-acting forms of nifedipine, which are taken once a day and are now more commonly prescribed than the older, short-acting versions.
Called calcium-channel blockers, these drugs dilate vessels by blocking the tiny pores that let calcium ions -- known to constrict vessels -- into the cells of artery walls.
Now, a study of guinea pigs suggests a molecular mechanism for ischemia that explains the action of calcium-channel blockers and may also reveal how some diabetes drugs boost insulin supplies, researchers say.

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