Blood Pressure Medications - Medications For Heart Disease: Heart Disease

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Blood pressure medications

For many years, doctors used diuretics — sometimes known as water pills — to treat high blood pressure. Although diuretics remain a mainstay of blood pressure treatment because they are cheap and effective, a flood of other drugs have become available since the 1980s. In addition, a large meta-analysis comparing the various options concluded that the five categories of drugs currently available are equally effective for most people. Work with your doctor to determine the best type of medication for you.

It is important to keep in mind, though, that most people with hypertension do not get their blood pressure under control with the starting dose of the first drug chosen. At that point, two philosophies exist about what to try next. Some doctors increase the dosage of the first drug to see if it will bring blood pressure down to target levels. The advantage of this approach is simplicity, as the person being treated takes one pill per day. A second approach is to use low doses of two or more blood pressure drugs that work in different ways. This approach minimizes the likelihood of side effects, but may be harder to follow, as it requires taking two or more pills per day. It may also be more expensive for the person being treated, as he or she may face additional copayments or out-of-pocket expenses for the drugs. A compromise approach is to use combination medicines that include, for example, both an ACE inhibitor and a low-dose diuretic (see "Combination medications"). This is convenient, but many combinations are available only in brand-name forms and are thus more expensive.

Diuretics

Thiazide diuretics work by reducing the amount of water in the body and increasing the flow of urine. These medications also reduce high blood pressure so effectively that they are recommended as initial treatment for most people with hypertension, either alone or in combination with another blood pressure medication. Many are now available in generic form, which means they are inexpensive. Commonly used thiazide diuretics include chlorthalidone (Hygroton, Thalitone) and hydrochlorothiazide (Microzide, HydroDIURIL), although there are many others.

Study after study has shown that diuretics are effective. Indeed, a 2002 report from ALLHAT (the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial) in the Journal of the American Medical Association showed that diuretics were just as effective as two newer medications: the calcium-channel blocker amlodipine (Norvasc) and the ACE inhibitor lisinopril (Prinivil, Zestril). What's more, diuretics boost the effectiveness of other antihypertensive medications, so you benefit more from multidrug therapies. But diuretics do have some drawbacks. If you have trouble with urination, diuretics may aggravate the situation. These drugs can also lower potassium levels (possibly causing leg cramps), although potassium-sparing diuretics are available. Finally, diuretics can cause fatigue and may raise blood sugar, increasing the risk for diabetes. Even with all the caveats, however, diuretics provide the foundation of treatment for high blood pressure.

Angiotensin-converting–enzyme (ACE) inhibitors

These blood pressure drugs dilate blood vessels. They work by blocking production of angiotensin, a blood vessel–constricting protein. In addition to controlling high blood pressure, ACE inhibitors have long been prescribed for people with heart failure. Studies have shown that these drugs also help in other situations. They help to preserve heart function after heart attacks, protect the kidneys in people with diabetes, and slow the progression of atherosclerosis. The most common problem is a persistent cough, which prompts 1 in 10 people to stop taking ACE inhibitors.

Angiotensin-receptor blockers (ARBs)

Angiotensin-receptor blockers (ARBs) provide an alternative to ACE inhibitors. ARBs work in a slightly different way from ACE inhibitors to restore normal blood flow: Instead of blocking production of angiotensin, ARBs prevent this protein from exerting its blood vessel–constricting effects in the body. When ARBs were first introduced, it was not clear whether they worked as well as ACE inhibitors. Two major clinical trials reported in 2003 that they do — at least for some people.

The CHARM study (short for Candesartan in Heart Failure: Assessment of Reduction in Mortality and Morbidity) compared the ARB candesartan (Atacand) with a placebo in more than 7,600 people with long-term heart failure. In the candesartan group, 23% died during the three-year study, compared with 25% in the placebo group. That survival advantage may not sound like much, but apply it to five million Americans with heart failure and it translates into longer lives for thousands. The VALIANT study (short for Valsartan in Acute Myocardial Infarction Trial) involved more than 15,000 heart attack survivors with heart failure or damaged left ventricles (compromising the heart's ability to pump blood). The researchers found that people taking the ARB valsartan (Diovan) fared just as well in terms of health outcomes (such as prevention of another heart attack) as those taking the ACE inhibitor captopril (Capoten).

ACE inhibitors remain the recommended first-line therapy for most people because they are much less expensive and have a longer track record than ARBs. But the CHARM and VALIANT studies showed that ARBs provide good alternatives if you can't take an ACE inhibitor. ARBs include candesartan, valsartan, irbesartan (Avapro), and losartan (Cozaar).

Beta blockers

Beta blockers are among the most commonly used drugs for controlling cardiac ischemia and hypertension. There are many types of beta blockers on the market, but all act by interfering with epinephrine (adrenaline), a hormone that normally stimulates the heart to beat faster and stronger. Beta blockers slow the heart rate and decrease cardiac output, lowering blood pressure and decreasing the amount of work the heart must do. By lowering the oxygen needs of the heart, beta blockers help prevent or relieve ischemia.

In some people, however, beta blockers also have side effects, such as erectile dysfunction and fatigue. In particular, people with asthma, heart failure, or diabetes should be cautious about taking this class of medications because of the possibility that such drugs could worsen these conditions.

However, some of the newer beta blockers are less likely to cause side effects because they act more selectively on the heart than on other parts of the body. These "partially selective" beta blockers include metoprolol (Lopressor, Toprol XL) and atenolol (Tenormin). In any case, these drugs are so effective in treating coronary artery disease that — despite their potential side effects — they are often tried in people with problems such as heart failure or diabetes because their benefits outweigh the risks.

Calcium-channel blockers

Calcium-channel blockers are vasodilators: By dilating the coronary arteries, they increase blood flow to the heart and cut its workload by reducing blood pressure and the force of the heart's contractions. The first generation of calcium-channel blockers were short-acting; some studies suggested they might be hazardous in certain people with heart disease. But the newer, long-acting calcium-channel blockers appear safe and effective in controlling high blood pressure. As a result, they have been endorsed as a first-line treatment for blood pressure.

In contrast to beta blockers, there is thus far no evidence that calcium-channel blockers improve survival after a heart attack in people with coronary artery disease. But they are useful for people who don't get adequate relief from beta blockers or nitrates. And calcium-channel blockers are more effective than beta blockers for preventing angina due to coronary spasm.

They also help people with high blood pressure who can't tolerate the side effects of relatively high doses of beta blockers or nitrates. Calcium-channel blockers are less likely to cause depression and fatigue than beta blockers are, and they have fewer side effects than nitrates do. They're also more convenient than nitrates, in most cases needing to be taken only once a day.

Last updated:	May 03, 2007