People
with heart valve problems are told to take antibiotics
before certain dental procedures in order to prevent bacterial
endocarditis. This disease can be triggered by bacteria
disrupted by tooth scaling, dental implantation, and other
invasive procedures. The bacteria goes into the bloodstream
and become lodged in the innermost layers of the damaged
heart valves. It is potentially fatal and can be well
underway before symptoms ever appear. To treat after the
fact might very well be too late. But antibiotic therapy
in itself can cause harm. And some researchers have questioned
the universal preventive antibiotics recommendation because
bacterial endocarditis is an uncommon disease.
For
a 2004 Cochrane* review entitled, “Penicillins for the
prophylaxis of bacterial endocarditis in dentistry,” R.
Oliver and colleagues searched the published medical literature
to find studies that proved the benefits of preventive
antibiotics outweigh the harm for high-risk people facing
an invasive dental procedure. All that could be found
was one case-control study conducted in The Netherlands,
and its results are inconclusive.
The
Cochrane reviewers also found a population study published
in 2000 in the American cardiac journal, Circulation that
quantified the risk of bacterial endocarditis and the
risk of taking antibiotics. It estimated that people taking
penicillin were five times more likely to die from an
allergic reaction to this antibiotic than from endocarditis.
The
Cochrane authors concluded: “There is no evidence about
whether penicillin prophylaxis is effective against bacterial
endocarditis in people at risk who are about to undergo
an invasive dental procedure. There is a lack of evidence
to support published guidelines in this area. It is not
clear whether potential harms and costs of penicillin
administration outweigh any beneficial effect. Ethically
practitioners need to discuss the potential benefits and
harms of antibiotic prophylaxis with their patients before
a decision is made about administration.”
*The
abstracts from all Cochrane reviews are available at www.thecochranelibrary.com
. See “Penicillins for the prophylaxis of bacterial
endocarditis in dentistry”.
--
Maryann
Napoli, Center for Medical Consumers © April 2005
