Antibiotics Prior to Dental Procedures: Big Change in Recommendations
Posted by medconsumers on July 1, 2007
For over a half century, millions of Americans with common heart valve problems, such as mitral-value prolapse, were told to start taking preventive antibiotics prior to undergoing routine dental procedures. To ignore this standard recommendation is to risk a potentially life-threatening case of bacterial endocarditis triggered by the dental procedure. Or so went a widely held belief that has been revised recently by the American Heart Association.
The AHA now restricts its preventive antibiotics advice to a much smaller group of people—those with serious heart conditions. The new guidelines were published recently in the journal, Circulation, where the AHA acknowledged its longstanding policy was based on expert opinion rather than evidence.
The AHA appointed a writing group comprised of people selected for their expertise in the prevention and treatment of endocarditis. After reviewing all relevant studies, the AHA writing group concluded that the odds of suffering a serious adverse reaction to the antibiotics are higher for most people with heart conditions than their odds of getting endocarditis due to a dental procedure. In other words, endocarditis is a rare possibility. This is similar to the conclusion of a 2004 review of all relevant studies on this topic conducted by the Cochrane Collaboration.
Central to the now-outdated AHA recommendations was the concern that even the most routine of dental procedures, such as tooth scaling, could let loose bacteria into the bloodstream. Theoretically, the bacteria would lodge on abnormal heart valves or other damaged heart tissue and cause endocarditis, an infection of the heart’s inner lining (endocardium) Ironically, the AHA guideline writers said that the chances of developing endocarditis from the more mundane everyday activities, such as tooth brushing, flossing, and use of toothpicks, are higher than getting it during a dental procedure.
On another ironic note, the AHA writing group found that studies involving the antibiotics typically prescribed before dental procedures—penicillin or amoxicillin—failed to prove that either drug is effective in reducing the release of bacteria into the bloodstream. (The studies had compared drug-treated people with untreated people who underwent the same dental procedures.) Also, there is no evidence to show that amoxicillin, the antibiotic of choice since 1990, can reduce the risk of or prevent endocarditis.
The new AHA guidelines now confine preventive antibiotics to people at the very highest risk for endocarditis, including those who have had the disease, and those with a prosthetic heart valve, congenital heart disease, hypertrophic cardiomyopathy or cardiac valvulopathy (after heart transplant). A single antibiotic dose before the dental procedure is sufficient for people in these circumstances.
Mitral Valve Prolapse
People with mitral valve prolapse (MVP), estimated to be about 18% of the population, are now freed from the need to take preventive antibiotics. The AHA writing group noted that the incidence of endocarditis is extremely low in the entire population of people with MVP. Moreover, the disease does not have the same deadly consequences in people with MVP as it does for those with the above-mentioned highest risks.
Bottom Line: A 50-year-old health policy without much supporting evidence has been revised. For most people with heart valve problems, antibiotics before a dental procedure pose more of a threat to health than the rare possibility of developing endocarditis. Furthermore, there is no evidence to show that antibiotics can reduce the risk of endocarditis. The American Dental Association endorsed the new guidelines.
Maryann Napoli, Center for Medical Consumers ©