RT Journal Article SR Electronic T1 Prophylaxis for infective endocarditis. Who needs it? How effective is it? JF Canadian Family Physician JO Can Fam Physician FD The College of Family Physicians of Canada SP 2248 OP 2255 VO 46 IS 11 A1 N Press A1 V Montessori YR 2000 UL http://www.cfp.ca/content/46/11/2248.abstract AB OBJECTIVE To review guidelines for using antibiotic prophylaxis to prevent infective endocarditis, and to present recent changes and controversies regarding these guidelines. QUALITY OF EVIDENCE Data are from physiologic and in vitro studies, as well as studies of animal models, and from retrospective analyses of human endocarditis cases. Systematic reviews and guidelines are also examined. As no randomized clinical trials have examined prophylaxis for bacterial endocarditis, many recommendations presented are based on consensus guidelines. MAIN MESSAGE Antibiotic prophylaxis to prevent bacterial endocarditis should be used in high- and moderate-risk patients with cardiac disease. It should be given before procedures in which bacteremias are likely with organisms that cause endocarditis, such as viridans streptococci. For most procedures, a single dose of amoxicillin (2 g by mouth 1 hour before the procedure) is sufficient to ensure adequate serum levels before and after the procedure. CONCLUSION Infective endocarditis continues to have high rates of morbidity and mortality. Antibiotic prophylaxis, therefore, is important to combat this preventable disease. For high- and moderate-risk patients with cardiac disease, the cost-benefit ratio favours prophylaxis.