Common Blood Pressure Drug May Not Be So Useful for Heart
Dec. 7, 2000 -- A new study suggests doctors should be cautious
about prescribing certain medications that lower high blood pressure. An
analysis of nine different studies finds that one popular class of these drugs
is less effective in preventing heart-related problems and may actually
increase the risk of heart attacks and heart failure.
Doctors who conducted the analysis say there is no reason for
patients taking these drugs, known as calcium-channel blockers, to be overly
concerned. Rather, the study is meant to reiterate to doctors that these drugs
should never be given as an initial treatment, or first-line therapy, for
people with high blood pressure, says Marco Pahor, MD, author of the study
appearing in this week's issue of The Lancet.
His study compared results from nine different blood
pressure-lowering trials involving over 27,000 people. Patients in the trials
received various drugs to lower their high blood pressure including
calcium-channel blockers, ACE inhibitors, diuretics and beta blockers. The last
two are older medications that doctors have used for years to effectively lower
Compared with people who took other drugs, people who took
calcium-channel blockers to lower blood pressure had a 26% higher risk of heart
attack, a 25% higher risk of heart failure, and a 10% higher risk of combined
major heart disease.
"Doctors should limit the use of calcium-channel blockers
unless other agents are not effective in lowering blood pressure or
contraindicated for the patient because of side effects," says Pahor,
professor of medicine and director of the Sticht Center on Aging at Wake Forest
University School of Medicine in Winston-Salem, N.C.
Another study in the same issue of the journal finds that
compared with ACE inhibitors, calcium-channel blockers increase the risk of
heart disease by 19% and the risk of heart failure by 18%. That study included
over 26,000 people with high blood pressure.
In an editorial that accompanies both of the studies, two
experts from Tulane University School of Medicine in New Orleans, say the
results are consistent with what a panel of experts said three years ago. At
that time, the panel recommended giving only diuretics or beta blockers for the
initial treatment of high blood pressure.
Jiang He, MD and Paul Whelton, MD, say these newer studies
being reported this week "also provide support for the use of ACE
inhibitors as initial choice of [blood-pressure-lowering] therapy. ACE
inhibitors may be especially useful in patients who are at high risk of heart
failure," they say. Some doctors favor combining ACE inhibitors with the
older drugs and studies are in progress to determine how to best accomplish
All the experts say, however, that the new studies should not
be interpreted to mean that calcium-channel blockers are not useful drugs or
that they are harmful. In fact, Pahor's study found them to be just as
effective as the other drugs at lowering blood pressure. But, he says the other
drugs may have additional benefits that calcium-channel blockers don't have,
which is why they should always be used first. Calcium-channel blockers also
appear to be fairly effective at reducing the risk of stroke among people with
high blood pressure, so he and Whelton say one scenario in which they could be
used as the initial treatment might be in people with a very high risk of
stroke but a low risk of heart disease.