Too Few Heart Patients Take Antibiotics Before Dental Work

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July 5, 2000 -- Last year, 52-year-old Richard Collett was diagnosed with a heart condition called mitral valve prolapse and regurgitation.

Whenever he goes to the dentist, he is reminded of his condition, in which one of the heart valves is leaky and allows some blood to flow backward between beats. "My heart doctor recommended that I take antibiotics whenever I have dental work, so I always take the antibiotics as prescribed by my dentist," says Collett, a real estate manager from Tampa, Fla.

Like many Americans, he needs to take antibiotics before having dental work to prevent a potentially fatal heart infection. "I hate taking pills," Collett says. "But when it comes to my heart, I'm not taking any chances."

But too many of these people are taking chances, according to a study published in the Journal of the American Medical Association. Many who need antibiotics before having dental work aren't taking them, and other dental patients are taking antibiotics needlessly.

"The bottom line of our study is that about 40% of patients who need preventive antibiotics for dental work and similar procedures aren't taking them, and that 25% of patients who don't need them are taking them," researcher Warren J. Manning, MD, tells WebMD. Manning is an associate professor of medicine and radiology at Harvard Medical School.

In 1955, the American Heart Association (AHA) first recommended that patients with certain heart conditions -- including artificial, leaking, or thickened heart valves -- take antibiotics before dental work or other procedures in the mouth or intestinal tract where bleeding is likely. Bacteria released during these procedures can enter the bloodstream, and may lodge in the damaged heart valves, where they can infect the heart and release clumps of bacteria that can plug up blood vessels, causing strokes.

Fortunately, this heart disease, called endocarditis, is a very rare complication, and can easily be prevented by giving antibiotics to those most at risk. Unfortunately, it can be life threatening and difficult to treat. Since almost three-fourths of those who get endocarditis already have valve damage or other heart problems, the AHA recommends that these patients take antibiotics one hour before dental work or similar procedures.


In 1997, the AHA revised its guidelines to clarify which patients should receive antibiotics, and to recommend a simpler dosing schedule so patients would be more likely to take them. "Despite the intensive efforts of the AHA ... to make its 1997 guidelines as user friendly as possible, misconceptions remain," says Thomas J. Pallasch, DDS, MS. Pallasch, a professor of pharmacology and periodontics at the University of Southern California School of Dentistry in Los Angeles, reviewed the study for WebMD.

For example, Pallasch explains that "[some] dental treatment procedures not associated with significant bleeding no longer require antibiotics ... even in the highest-risk patients, and [the dentist is] the one to make this decision."

Manning's study looked at about 200 patients seen at the Beth Israel Deaconess Medical Center in December 1997. As directed by the new AHA guidelines, all the study patients had an echocardiogram, a test that uses sound waves to look at the heart and its valves.

Almost half of the patients who took part in the study had abnormal echocardiograms, suggesting that they needed antibiotics before dental work. Almost 90% of the patients who were at high risk for heart infection were told by their doctors to use preventive antibiotics, but only 60% of those at moderate risk got this advice. About 25% of those at low risk of heart infection -- who the AHA guidelines say don't need antibiotics -- were instructed to take them.

"The problems with taking antibiotics when you don't need them are the inconvenience, the cost, and the risk of an allergic reaction," Manning says. "On the other hand, if you need antibiotics and don't take them, there could be a life-threatening complication."

When asked for his recommendations, Manning says: "If you're taking antibiotics and it's been awhile since your situation has been reviewed, you should ask your doctor if you still need them. If you've had an echocardiogram and you're not using antibiotics for dental procedures, you should ask your doctor to review the echocardiogram to see if you do need them."

Although most patients in Manning's study followed their doctor's advice to take antibiotics, 13% did not. Better education for both doctors and patients may allow more appropriate antibiotic use while avoiding misuse, the study says.


Vital Information:

  • People with certain heart conditions, especially those involving the heart valves, should take antibiotics one hour before dental work or similar procedures to avoid a potentially fatal heart infection called endocarditis.
  • A study published in the Journal of the American Medical Association showed that about 40% of those who should take preventive antibiotics were not advised by their doctors to do so, and about 25% of those who are at low risk of endocarditis take antibiotics needlessly.
  • Patients with valve problems or other heart conditions should have an echocardiogram, and should consult their doctors about preventive antibiotic use.
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