Study Clouds Hypertension Drug Debate
Conflicting Studies Point to Need for Combination of Blood Pressure Drugs
Feb. 12, 2003 -- New research from Australia will no doubt add
to the confusion about which high blood pressure drugs work best. The study
appears to contradict a large, U.S. government investigation that made
headlines late last year by finding that the oldest and cheapest hypertension
drugs are superior to newer and more expensive medications.
In the Australian study, older men with high blood pressure who
took one of the newer drugs, known as ACE inhibitors, had a better outcome than
those treated with traditional diuretics. In the U.S. trial, which compared
four different classes of hypertension drugs, diuretics were reported to be
more effective for preventing fatal and non-fatal heart attacks than ACE
inhibitors, calcium channel blockers, and alpha-adrenergic blockers.
But hypertension experts contacted by WebMD say the studies are
not necessarily contradictory. They add that it is becoming increasingly clear
that most patients respond best to a combination of drugs, which should usually
include a diuretic.
"Unfortunately, most of the media coverage of this issue
has come down to 'this drug is better than that one' or 'that drug is better
than this one,'" cardiologist Edward D. Frohlich, MD, tells WebMD. "The
truth is that 75% to 85% of people require multiple drugs to control their
hypertension, and the best treatment varies from patient to patient."
Diuretics were once the only choice for treating hypertension,
but their use has declined with the introduction of the newer drugs. More than
24 million Americans take high blood pressure medications, and the costs vary
widely -- diuretics cost approximately $25 per year, ACE inhibitors about $250,
and calcium channel blockers about $500.
The Australian trial, reported Feb. 13 in TheNew
England Journal of Medicine, included 6,083 men and women with high blood
pressure over the age of 64 being treated by family practitioners. The patients
received either a diuretic or ACE inhibitor to control their blood pressure and
were then followed for four years.
At follow-up, both groups had similar declines in blood
pressure, but there were slightly fewer heart attacks and deaths among patients
on ACE inhibitors. The difference in outcome was most pronounced among elderly
In an editorial accompanying the study, Frohlich writes that
the apparently contradictory findings from the Australian and U.S. trials might
be explained by ethnic differences among the two study populations. Whites made
up 95% of the study group in the Australian study, and 35% of the patients
taking part in the U.S. study were blacks. Blacks are known to respond better
to diuretics than other classes of hypertension drugs.
He says that elderly patients often have medical conditions
that influence the choice of blood pressure treatment. Initial treatment for
patients with heart failure should include both a diuretic and an ACE
inhibitor, Frohlich writes, and those who have had heart attacks seem to do
best with an ACE inhibitor and another class of drug known as beta