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High Blood Pressure Medicine
High Blood Pressure Medicines
Angiotensin converting enzyme inhibitors (ACE Inhibitors) and angiotensin receptor blockers
High Blood Pressure medicine angiotensin converting enzyme (ACE) inhibitors and the angiotensin receptor blocker (ARB) high blood pressure medicine both affect the renin-angiotensin
hormonal system, which, as mentioned previously, helps regulate the high blood pressure. The ACE inhibitors work by blocking (inhibiting) an
enzyme that converts the inactive form of angiotensin in the blood to its active form. The active form of angiotensin constricts or narrows
the arteries, but the inactive form cannot. With an ACE inhibitor as a high blood pressure medicine, 50 to 60 percent of Caucasians usually
achieve good blood pressure control.
In patients who have high blood pressure in addition to certain second diseases, a combination of an ACE inhibitor and an ARB drug may be
effective in controlling the high blood pressure and also benefiting the second disease. For example, while treating hypertension, this combination
of drugs can reduce the loss of protein in the urine (proteinuria) in certain kidney diseases and perhaps help strengthen the heart muscle in
certain diseases of the heart muscle (cardiomyopathies). Note that both the ACE inhibitor high blood pressure medicine and the ARB drugs are
not to be used in pregnant women.
Beta-blockers
Beta-blockers remain useful high blood pressure medicines in treating hypertension, especially in patients with a fast heartbeat while
resting, cardiac chest pain, or a recent heart attack. For example, beta-blockers appear to improve long-term survival when given to patients
who have had a heart attack. Whether beta-blockers can prevent heart problems in patients with high blood pressure any more than other
anti-hypertensive medicine, however, is uncertain. Beta-blockers may be considered as a high blood pressure medicine because they also may
treat co-existing medical problems. For example, beta-blockers can help treat chronic anxiety or migraine headaches in people with
hypertension. The common side effects of these drugs include depression, fatigue, nightmares, sexual impotence in males, and increased
wheezing in people with asthma. The beta-blocker high blood pressure medicines include atenolol (Tenormin), propranolol (Inderal), metoprolol
(Toprol), nadolol (Corgard), betaxolol (Kerlone), acebutolol (Sectral), pindolol (Visken), and bisoprolol (Zebeta).
Diuretics
Diuretics are among the oldest known high blood pressure medicines. They work in the tiny tubes of the kidneys to remove salt from the body.
Water also may be removed along with the salt. Diuretics may be used as single high blood pressure medicine. More frequently, however, low
doses of diuretics are used in combination with other medicine to enhance the effect of the other medications.
Occasionally, when salt retention causing accumulation of water and swelling is a major problem, the more potent, so-called, loop diuretics
may be used in combination with other anti-hypertensive medications. (The loop diuretics are so called because they work in the loop segment
of the kidney tubules to eliminate salt.) The most commonly used diuretics include hydrochlorothiazide
(Hydrodiuril), the loop diuretics furosemide (Lasix) and torsemide (Demadex), the combination of triamterene and hydrochlorothiazide
(Dyazide), and metolazone (Zaroxolyn). For those individuals who are allergic to sulfa drugs, ethacrynic acid, a loop diuretic, is a good
option.
Calcium channel blockers (CCBs)
Calcium channel blockers inhibit the movement of calcium into the muscle cells of the heart and arteries. The calcium is needed for these
muscles to contract. These drugs, therefore, lower blood pressure by decreasing the force of the heart's pumping action (cardiac contraction)
and relaxing the muscle cells in the walls of the arteries. Three major types of calcium channel blockers are used as high blood pressure
medicine. One type is the dihydropyridines, which do not slow the heart rate or cause other abnormal heart rates or rhythms. These drugs
include amlodipine (Norvasc), sustained release nifedipine (Procardia XL, Adalat CC), felodipine (Plendil), and nisoldipine (Sular).
The other two types of calcium channel blockers are referred to as the non-dihydropyridine agents. One type of high blood pressure medicine
is verapamil (Calan, Covera, Isoptin, Verelan) and the other high blood pressure medicine is diltiazem (Cardizem, Tiazac, Dilacor, and
Diltia). Both the dihydropyridines and the non-dihydropyridines are very useful when used alone or in combination with other
anti-hypertensive agents. The non-dihydropyridines, however, are not recommended in congestive heart failure or with certain arrhythmias.
Sometimes, however, these same dihydropyridines are useful in preventing certain other arrhythmias.
Alpha-blockers
Alpha-blockers are medicines that lower blood pressure by blocking alpha-receptors in the smooth muscle of peripheral
arteries throughout the tissues of the body. The alpha-receptors are part of the sympathetic nervous system, as are the beta-receptors. The
alpha-receptors, however, serve to narrow (constrict) the peripheral arteries. Accordingly, the alpha-blockers cause the peripheral arteries
to widen (dilate) and thereby lower the high blood pressure.
Alpha-blockers are particularly useful in patients with enlargement of the prostate gland because these reduce
the problems associated with urinating. Alpha-blockers alone, however, have a relatively small blood pressure-lowering effect. Accordingly,
when high blood pressure coexists with prostatic enlargement, another anti-hypertensive medicine should be used together with an
alpha-blocker. For example, tamsulosin (Flomax) or alfuzosin (Uroxatral) are alpha-blockers that work well in combination with other high
blood pressure medicines.
Clonidine
Clonidine (Catapres) is an antihypertensive drug that works centrally. That is, it works in a control center for the sympathetic nervous
system in the brain. This high blood pressure medicine is referred to as a central alpha agonist because it stimulates alpha-receptors in the
brain. The result of this central stimulation, however, is to decrease the sympathetic nervous system outflow and to decrease the stiffness
of the peripheral arteries. Clonidine lowers the blood pressure, therefore, by relaxing the peripheral arteries throughout the body. This
high blood pressure medicine is useful as a second or third line high blood pressure medicine choice for lowering blood pressure when other
high blood pressure medicines have failed. It also may be useful on an as-needed basis to control or smooth out fluctuations in the blood
pressure. This drug tends to cause dryness of the mouth and fatigue so that some patients do not tolerate it. Clonidine comes in an oral form
or as a sustained release skin patch.
Minoxidil
Minoxidil is the most potent of the high blood pressure medicines that lower blood pressure by dilating the peripheral arteries. This drug, however, does not work through the peripheral sympathetic nervous system, as do the alpha and beta-blocker drugs, or through the control center in the brain, as does clonidine. Rather, it is a muscle relaxant that works directly on the smooth muscle of the peripheral arteries throughout the body. Minoxidil is used for patients who have not responded to any other medications. It must be combined with a beta-blocker or clonidine to prevent an increase in the heart rate and with a diuretic to prevent retention of fluid. Minoxidil may also increase hair growth. For more information, please see the drug monograph on Minoxidil.
Tags: high blood pressure medicine,ace inhibitors,
beta-blockers,beta blockers,
calcium channel blockers, diuretics,
alpha blockers, clonidine,
minoxidil, hypertension,
medicine, medication
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