Diuretics most effective hypertension drug
Results from a five-year trial support this class of
drugs as a first-line medication for high blood pressure treatment.
By
Susan J. Landers, AMNews staff.
Jan. 20, 2003. Additional information
Washington -- Heads up! Patients
may soon be asking if they should switch their high blood pressure
medications to an older, and much cheaper, class of drugs -- diuretics.
Findings from a federal study, published in the Dec. 18, 2002 JAMA,
have determined that the medication first introduced in the 1950s is often
more effective than newer and more costly drugs at lowering high blood
pressure. Those findings are generating a great deal of attention.
The trial was the largest to test diuretics against the newer calcium
channel blockers and ACE inhibitors. Beta-blockers were not included. An
arm of the trial to test alpha-adrenergic blockers was stopped in March
2000 because of increased cardiovascular problems for those subjects.
While all three classes of drugs tested during the nearly
five-year-long trial lowered blood pressure and reduced cardiovascular
complications, diuretics were more likely to prevent heart failure and
strokes, especially among African-Americans. There was no difference in
overall deaths among participants.
Many of the participants were prescribed a second drug to control their
blood pressure.
The specific drugs tested in the trial were the diuretic chlorthalidone,
the calcium channel blocker amlodipine and the ACE inhibitor lisinopril.
50 million Americans have high blood pressure.
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The implications of the findings are enormous. Some 50 million
Americans have high blood pressure, increasing their risks for heart
attack, heart failure and stroke.
This large potential use for antihypertensive drugs prompted a flood of
such medications onto the market over the years. As a result, physicians
are able to choose from among more than 100 approved medications
representing seven major drug classes.
But the question has always been: Which drugs work best?
The study investigators believe the trial, called ALLHAT for
Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack
Trial, answers that question.
"The take-home message is that doctors should begin drug treatment for
high blood pressure with a diuretic," said epidemiologist Paul Whelton,
MD, senior vice president for health sciences at Tulane University Health
Sciences Center in New Orleans and an ALLHAT regional coordinator.
"For patients whose high blood pressure is already being treated with
medication other than a diuretic, physicians should consider switching to
a thiazide-type diuretic or adding diuretics to the existing regimen,"
said Dr. Whelton, during a December 2002 media briefing on the trial's
findings.
High blood pressure is a major risk factor for heart attack, heart
failure and stroke.
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Dr. Whelton acknowledged that physicians still need to take into
consideration other conditions that patients may have that could influence
drug choice, such as angina pectoris.
The cost of treating hypertension would drop dramatically if there is a
major shift to diuretics as a first-line treatment or as part of a
regimen.
For example, according to the JAMA article, previous data
demonstrated that diuretic use declined from 56% to 27% of
antihypertensive prescriptions between 1982 and 1992. However, the health
care system would have saved $3.1 billion in estimated cost of
antihypertensive drugs had the pattern of prescriptions for treatment of
hypertension remained at the 1982 level.
Diuretics would also be much more affordable for patients who lack
health insurance or coverage for medications. The drugs cost six cents to
10 cents per day compared with a cost of about $1 per day for ACE
inhibitors.
To help spread the word to doctors that diuretics should be seriously
considered as a treatment for high blood pressure, a committee was
appointed to develop new clinical guidelines.
"We are deeply committed to applying these research findings in order
to improve the health of the nation," said Claude Lenfant, MD, director of
the Heart, Lung, and Blood Institute, which sponsored the trial.
The 700 investigators involved in the trial will also help disseminate
the findings, and medical organizations will be asked to pitch in, said
Curt Furberg, MD, chair of the ALLHAT steering committee and a professor
of public health sciences at Wake Forest University Baptist Medical Center
in Winston-Salem, N.C. "We will go full press," he said.
The trial also included a cholesterol-lowering study that supported
current recommendations that lowering elevated cholesterol levels through
lifestyle changes and drug treatment remains crucial for the prevention of
heart attacks and strokes, said Jeffrey L. Probstfield, MD, a member of
the ALLHAT steering committee and a professor of medicine and epidemiology
at the University of Washington Health Sciences Center in Seattle.
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ADDITIONAL INFORMATION:
Study details
Key design features of ALLHAT, the Antihypertensive and
Lipid-Lowering Treatment to Prevent Heart Attack Trial, a five-year
study:
- The randomized, double-blind trial included more than 42,000
participants age 55 and older who had hypertension measuring at least
140/90 mm Hg. All had at least one other risk factor for heart
disease, such as smoking or type 2 diabetes.
- The researchers made an effort to recruit a variety of
participants. About 47% were women, 47% were non-Hispanic whites, 32%
were blacks and 36% had diabetes.
- The study was conducted at 623 clinical sites in the United
States, Canada, Puerto Rico and the Virgin Islands. About 7,000
participants were treated at Veterans Affairs clinics.
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Copyright 2003 American Medical Association. All
rights reserved.
