Docs should lay off beta-blocker
prescriptions for high blood pressure, concludes a review
in the August 14 Journal of the American College
of Cardiology. They’re not as effective as
other hypertension drugs at preventing strokes and cardiovascular
disease — and they have more side effects.
“Year after year, the use
of betablockers has been increasing in the United States,”
Dr Franz Messerli, a New York cardiologist and one of
the study authors, told Heartwire. “This
is despite the fact that we showed many, many years
ago, for hypertension, that there is basically no evidence
for their use.”
But not all MDs agree. “That’s
hogwash,” says Dr Norman Campbell, author of the
2007 Canadian Hypertension Society (CHS) guidelines
on hypertension. Dr Campbell says that Canadian studies
have concluded that beta-blockers work just as well
as diuretics, calcium-channel blockers and ACE-inhibitors
for uncomplicated hypertension in young adults. But
he advocates strongly against their use in the elderly.
FOR
BETA OR WORSE
Beta-blockers have been long-favoured meds to lower
blood pressure and reduce the risks of coronary artery
disease and heart failure. But they only produce a positive
outcome because they’re often used in conjunction
with diuretics, claim the review authors. In fact, “patients
who received the combination of beta-blockers and diuretics
fared consistently worse than those on diuretics alone,”
they write. The blood pressure pills have been linked
to an increased risk of diabetes, stroke and a host
of side effects ranging from depression to sexual dysfunction.
They also have dismal compliance rates, says the review.
Dr Campbell says that attitude
is outdated. “It goes back to the 60s and to poorly-done
studies. None of those drugs have clear superiority,
and adverse effects are no greater with beta-blockers
than the others.”
He points out the review focuses
particularly on atenolol, an early beta-blocker. The
issues brought up are specific to atenolol and not betablockers
in general, and the newer generation ones are much safer,
he adds. He worries that swinging the pendulum too far
in the opposite direction would prevent those who actually
need the drugs from getting them.
AGE
RESTRICTIONS
Beta-blockers have their uses, the review authors concede.
Studies have shown that they reduce mortality and morbidity
in post-myocardial infarction patients and in those
with heart failure. They protect the hearts of those
patients and slow down their heart rate, Dr Messerli
explained to Heartwire. He says that a widespread
acceptance of beta-blockers is due to a “myth of
cardioprotection,” that’s based only on post-MI
studies.
But physicians shouldn’t extrapolate
those benefits to other situations, agree both Dr Messerli
and Dr Campbell. Elderly patients with hypertension
show a reduced betaadrenergic responsiveness, so the
drugs don’t work well on this population.
But whether for the elderly, or
for regular hypertension, physicians are reluctant to
switch to other meds. “Many of them feel that if
their patient is already on them and tolerating them
well, then why rock the boat?”explains Dr Campbell.
The review authors found a similar attitude in American
docs who rank beta-blockers highest in terms of their
protection against cardiovascular events. They blame
the misconceptions on deceptive marketing by pharmaceutical
companies.
Dr Campbell has another explanation.
“There are always knowledge translation issues,”
he says. “Family physicians have to deal with everything
under the sun, from colds to depression to pneumonia,
and hypertension is just one issue. The message maybe
didn’t get to them.”
European recommendations still
list them as first-line therapy for hypertension, while
the UK scrapped them altogether as a first-line therapy
in its 2007 guidelines. For now at least, the CHS is
sticking to its guns, saying a patient’s age should
be part of the decision to use them.
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