Battle of the High Blood Pressure Drugs
April 18, 2000 -- If you're among the one million Americans who use what's
called an alpha-blocker to treat your high blood pressure, this story concerns
A preliminary result from a large national study looking at blood pressure
medications finds the alpha-blocker Cardura is less effective in treating high
blood pressure than the less costly and more conventional treatment, a
diuretic. Diuretics decrease blood pressure by increasing urination.
There is nothing in the findings that state Cardura is harmful in any
way, just that it is not as effective as a diuretic for treating high blood
The primary goal of the study was to evaluate heart disease, both fatal and
non-fatal, and there was essentially little difference between the two drugs,
one of the researchers, Charles Ford, PhD, tells WebMD.
An advisory committee from the National Heart, Lung, and Blood Institute
(NHLBI), the sponsor of the study, recommended halting the part of the study
that involved Cardura in late January. The basis of that decision is outlined
in the April 19 issue of TheJournal of the American Medical
The Cardura portion of the study involved just under 25,000 patients.
Compared to the diuretic chlorthalidone, patients in the study using Cardura
had 25% more heart problems and were twice as likely to be hospitalized for
heart failure. The patients had slightly higher systolic blood pressures than
the chlorthalidone group, and were less likely to take their medicine. Both
drugs were similarly effective in preventing heart attacks.
The higher incidence of heart attacks and heart failure was
"foremost", says lead author Barry R. Davis, MD, PhD, in deciding to
discontinue with Cardura. Davis is with the University of Texas-Houston School
of Public Health.
Gerald Payne, MD, NHLBI scientific project officer for the study, tells
WebMD, "we can't say that [Cardura] causes these events ... It just doesn't
prevent them as much as the diuretics. That's as far as we can state from this
study," he says.
"Clearly, the diuretic was superior to [Cardura] in preventing ... heart
failure and [Cardura] did not seem to be any better at preventing the other
kinds of outcomes that we were looking at," Ford tells WebMD. He suggests
that it might be a good idea to start with the diuretic and then keep Cardura
"as a step two or step three drug to be added as needed." Ford is an
associate professor of biometry at University of Texas-Houston School of Public
According to a press release on the subject, the NHLBI is advising high
blood pressure patients who take an alpha-blocker to consult with their doctors
about a possible alternative. If a patient is just starting drug treatment, an
alpha-blocker may not be the best choice for initial therapy. Other
alpha-blockers in the same class as Cardura are Hytrin and Minipres. Ford
doesn't say their recommendations apply to all alpha-blockers, but just that
Cardura was chosen as a "representative member of that class of