Which patients — The following are the highest risk conditions (see 'Patients at highest risk' above):


¦Prosthetic heart valves, including bioprosthetic and homograft valves.
¦A prior history of IE.
¦Unrepaired cyanotic congenital heart disease, including palliative shunts and conduits.
¦Completely repaired congenital heart defects with prosthetic material or device, whether placed by surgery or by catheter intervention, during the first six months after the procedure.
¦Repaired congenital heart disease with residual defects at the site or adjacent to the site of the prosthetic device.
¦Cardiac valvulopathy in a transplanted heart.

The following are the highest risk procedures (see 'Procedures that may result in transient bacteremia' above):


¦All dental procedures that involve manipulation of either gingival tissue or the periapical region of teeth or perforation of the oral mucosa.
¦Procedures of the respiratory tract that involve incision or biopsy of the respiratory mucosa.
¦Procedures in patients with ongoing GI or GU tract infection.
¦Procedures on infected skin, skin structure, or musculoskeletal tissue.
¦Surgery to place prosthetic heart valves or prosthetic intravascular or intracardiac materials. (See 'Special circumstances' above.)



Which antibiotic — The choice of antibiotic is patient and procedure specific.

For patients undergoing a dental procedure, who will be the majority of individuals for whom prophylaxis is appropriate, 
---the preferred regimen is oral amoxicillin 2 grams (ADULTS) given 30 to 60 minutes before the procedure. 
---Alternative regimens for patients with penicillin allergy or who are unable to take oral medication are shown below under the amox dose.


Children — Children given endocarditis prophylaxis should receive the same antibiotic regimens and dosing intervals as noted above. 
Equivalent pediatric doses for oral therapy are as follows:


¦Amoxicillin — 50 mg/kg to a maximum dose of 2 g
¦Azithromycin or clarithromycin — 15 mg/kg to a maximum dose of 500 mg
¦Clindamycin —20 mg/kg to a maximum dose of 600 mg
¦Cephalexin — 50 mg/kg to a maximum dose of 2 g

Equivalent pediatric doses for intramuscular or intravenous therapy are as follows:


¦Ampicillin — 50 mg/kg to a maximum dose of 2 g
¦Cefazolin or ceftriaxone — 50 mg/kg to a maximum dose of 1 g
¦Clindamycin — 20 mg/kg to a maximum dose of 600 mg
¦Vancomycin — 15 mg/kg to a maximum dose of 1 g