New guidelines regarding antibiotics to prevent infective endocarditis The American Heart Association recently updated its guidelines regarding which patients should take a precautionary antibiotic to prevent infective endocarditis (IE) before a trip to the dentist. The guidelines, published in Circulation: Journal of the American Heart Association, are based on a growing body of scientific evidence that shows that, for most people, the risks of taking prophylaxis antibiotics for certain procedures outweigh the benefits. These guidelines represent a major change in philosophy. The new guidelines show taking preventive antibiotics is not necessary for most people and, in fact, might create more harm than good. Unnecessary use of antibiotics could cause allergic reactions and dangerous antibiotic resistance. Only the people at greatest risk of bad outcomes from infective endocarditis — an infection of the heart's inner lining or the heart valves — should receive short-term preventive antibiotics before common, routine dental and medical procedures. Patients at the greatest danger of bad outcomes from IE and for whom preventive antibiotics are worth the risks include those with: artificial heart valves a history of having had IE certain specific, serious congenital (present from birth) heart conditions, including: unrepaired or incompletely repaired cyanotic congenital heart disease, including those with palliative shunts and conduits a completely repaired congenital heart defect with prosthetic material or device, whether placed by surgery or by catheter interventions, during the first six months after the procedure any repaired congenital heart defect with residual defect at the site or adjacent to the site of a prosthetic patch or prosthetic device a cardiac transplant which develops a problem in a heart valve.