In 2007, revised guidelines for prophylaxis against infective endocarditis were developed and endorsed by the American Dental Association, the Infectious Diseases Society of America, and the American Academy of Pediatrics. According to these latest guidelines:
All patients with porcine valve replacements should now routinely receive prophylaxis against methicillin- resistant Staphylococcus aureus (MRSA) prior to dental procedures.
Genitourinary or gastrointestinal operations or procedures require less intense prophylaxis than do oral or respiratory procedures.
In patients with prosthetic heart valves, the number needed to treat (NNT) to prevent one case of infective endocarditis is less than 1000.
Patients with hypertrophic cardiomyopathy are at higher risk than previously thought.
Prophylactic antibiotics are recommended for high-risk patients undergoing “procedures that involve manipulation of gingival tissue or the periapical region of teeth or perforation of the oral mucosa.” Such high-risk patients include those with (1) prior infective endocarditis, (2) prosthetic cardiac valves, (3) unrepaired cyanotic congenital heart defects, including palliative shunts and conduits, (4) congenital heart defects completely repaired with prosthetic material or a device, whether placed by surgery or by catheter intervention, during the first 6 months after the procedure, (5) repaired congenital defects with residual defects at the site or adjacent to the site of a prosthetic patch or prosthetic device, and (6) cardiac transplants with development of cardiac valvulopathy. Patient groups that may have received routine antibiotic prophylaxis in the past but are no longer candidates for it include those with mitral and aortic valve disease, rheumatic heart disease, or structural disorders like ventricular or atrial septal defects or hypertrophic cardiomyopathy, according to the AHA statement. Amoxicillin at a dose of 2 g (or 50 mg/kg in children) is recommended for most patients requiring antibiotics. This medication should be given to patients 30–60 minutes before the procedure. High-risk adults with penicillin allergy may receive cephalexin 2 g; clindamycin 600 mg; or either azithromycin or clarithromycin 500 mg. Routine antibiotic prophylaxis is not necessary before routine gastrointestinal or genitourinary procedures, including esophagogastroduodenoscopy or colonoscopy, but antibiotics may be considered prior to procedures designed to treat infections in the gastrointestinal or genitourinary tracts.