Prescription of Antibiotics for Prophylaxis to Prevent Bacterial Endocarditis

Abstract

Systematic review conclusion. There is no evidence that antibiotic prophylaxis before dental procedures is effective or ineffective against bacterial endocarditis in patients already at risk of developing the disease.Critical summary assessment. On the basis of evidence from one case-control study, no definite conclusion can be drawn on the usage of antibiotic prophylaxis before dental procedures.Evidence quality rating. Limited. Does prophylactic antibiotic administration before invasive dental procedures in people at increased risk of bacterial endocarditis influence mortality, serious illness or endocarditis incidence? The authors conducted a comprehensive search of six electronic databases from 1950 through June 2008. The initial search identified 980 abstracts of which the authors reviewed 118 full articles. The authors excluded 83 articles because they were discussion articles, editorials or guidelines and 34 articles because they were duplicate studies. They included one article, which was a case-control study. The one study that was included reported on all cases of endocarditis in the Netherlands during a two-year period from November 1986 through November 1988, according to the authors. In the study, the authors defined cases as patients who had a predisposing cardiac disease and had undergone a medical or dental procedure with a definite or possible indication for prophylaxis and developed endocarditis within 180 days of this procedure. In the study, control patients had one of the following pre-existing conditions: congenital heart defect, history of rheumatic fever, high risk of developing endocarditis with prosthetic heart valves or a history of endocarditis. Control patients were matched for age and had undergone a medical or dental procedure with a definite or possible indication for prophylaxis and had not developed endocarditis within 180 days of the procedure. Indications for “definite prophylaxis” were dental extraction and “dental root work,” and an indication for “possible prophylaxis” was dental scaling. Of 349 patients who developed native-valve endocarditis, 44 had undergone dental treatment with a definite or possible indication for prophylaxis. Seven of these patients had been treated with prophylactic antibiotics before the dental procedure. Of the patients meeting the criteria for the control group, 181 had undergone a dental procedure with a definite or possible indication for prophylaxis. Seventeen of the control patients had been administered prophylactic antibiotics before they underwent the dental procedure. The odds of development of endocarditis among those receiving antibiotic prophylaxis was 1.62 (95 percent confidence interval, 0.57–4.57). The authors did not locate any studies that assessed mortality, illness or other adverse effects. Since no conclusive evidence supporting a benefit was identified, the authors did not look for information on harms. There is no evidence that antibiotic prophylaxis is effective or ineffective against bacterial endocarditis when it is administered before an invasive dental procedure in people who are at risk of developing the disease.