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Facts About ALLHAT:
New Findings About Drugs to Lower High Blood Pressure and Cholesterol

Many drugs have been developed in recent years to treat high blood pressure (or hypertension) and high cholesterol, two major risk factors for heart disease. Recent findings from a major clinical study supported by the National Heart, Lung, and Blood Institute (NHLBI) offer new information about treating both conditions.

ALLHAT--the "Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial"--was a large study that began in 1994 and lasted 8 years. It had two parts: one compared effects of a diuretic (sometimes referred to as a "water pill") with three newer, more costly blood pressure-lowering drugs; the other compared the effects of a cholesterol-lowering statin drug and diet with those of "usual care," which included a diet and, at the start of the study, no cholesterol-lowering drug. Those in the usual care group were given a cholesterol-lowering drug later in the study when their doctor felt their condition needed it. The blood pressure trial involved more than 40,000 persons, aged 55 and older, who had hypertension. Of those, more than 10,000 who had moderately elevated cholesterol were in the cholesterol trial as well.

More information about each part-and what the findings mean for you--starts below. If you are being treated for high blood pressure and/or high cholesterol, do not make any changes without first talking with your doctor. Every drug has multiple effects, and the benefits of its use must be weighed against the risks to find the best treatment for each person.

Also, whether or not drug therapy is needed, treatment for both conditions includes lifestyle measures, such as becoming physically active, losing weight, if overweight, following a low-saturated fat, low-cholesterol eating plan, limiting dietary salt, and not smoking.

Blood pressure should be controlled to less than 140/90 mm Hg--even lower if you have certain conditions, such as diabetes or heart failure. Target levels for LDL (low-density lipoprotein, the "bad" cholesterol) depend on your risk for heart disease.

High Blood Pressure Study

All four of the drugs studied in ALLHAT are effective in lowering blood pressure. The study tried to find which was the best choice for starting treatment. Results show that diuretics work best to both lower blood pressure and prevent stroke and some forms of heart disease, including heart attack and heart failure. The newer drugs studied were a calcium channel blocker, an angiotensin converting enzyme (ACE) inhibitor, and an alpha-adrenergic blocker. Study of the alpha-adrenergic blocker was stopped early: Compared with those on the diuretic, those on the alpha-adrenergic blocker had substantially more cardiovascular problems, especially hospitalizations for heart failure.

The advice given here also includes another type of blood pressure drug called beta blockers. This drug was not studied in ALLHAT but prior trials found it effectively lowers blood pressure, and prevents heart problems and strokes.


  • If you need to begin drug treatment, you should definitely try a diuretic first.
  • Beta blockers are another option to begin treatment, especially if you're younger than age 60 and do not have diabetes or peripheral artery disease (in which blood flow becomes reduced, especially to the hands and feet). Beta blockers also may be needed if you're taking the drug for another condition, such as heart attack or heart failure. If you're now taking a beta blocker, talk with your doctor about your total health needs.
  • If you need multiple drugs to control your blood pressure-which is common-make one a diuretic. If you already take more than one drug but your blood pressure is not yet under control, talk with your doctor about adding a diuretic to your treatment; if you take more than one drug and your blood pressure is controlled, ask about switching one to a diuretic.
  • Your doctor may consider giving you a calcium channel blocker or ACE inhibitor if you can't take a diuretic.
  • If you have angina (chest pain from heart disease), you may need to take a calcium channel blocker. It should be used along with a diuretic. Check with your doctor.
  • Your doctor may consider prescribing an alpha-adrenergic blocker if you take more than one drug to control blood pressure and/or that drug is being used to treat benign prostatic hyperplasia. Talk with your doctor about your total health needs.

Cholesterol Study

The cholesterol study was not "blinded"-participants and their health care providers knew who was receiving which treatment. During the study, many of those in the usual care group were judged by their doctor to need, and so were given, a cholesterol-lowering drug. After 4 years, both groups had significant cholesterol reductions. The difference in cholesterol reductions between the groups was too small to show a difference in death rates and produced only a small, non-significant decrease in the rates of heart attacks and strokes in the statin group.


  • The findings are in line with those from other statin trials, considering the lesser differences in cholesterol between ALLHAT's two groups.
  • ALLHAT's findings leave unchanged current cholesterol treatment guidelines, which are based on statin trials with larger cholesterol reductions. You can reduce your risk of developing or dying from heart disease, heart attack, and stroke with lifestyle changes and, if needed, drug treatment. Talk with your doctor to find the best treatment for your health needs.

To Learn More

Contact the NHLBI Health Information Center at P.O. Box 30105, Bethesda, MD 20824-0105; by phone (301) 592-8573; or, online at

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