New guidelines and the development of an international consensus on recommendations for the antibiotic prophylaxis of infective endocarditis.

During the last five years there has been a considerable change in attitude towards antibiotic prophylaxis of endocarditis in many countries so that far fewer cardiac patients are advised to receive prophylaxis in comparison with previous years. Much greater emphasis is now given to the maintenance of good oral hygiene as the main method of preventing endocarditis and prophylaxis is only recommended for patients with the highest risk cardiac conditions undergoing dental procedures. Most countries have now abandoned prophylaxis for urological and gastrointestinal procedures. The UK National Institute for Health and Clinical Excellence guidance, which does not recommend prophylaxis for any group of patients undergoing dental procedures, is regarded as too extreme by many experts in other countries. The assertion that more patients would die from fatal anaphylaxis after oral amoxicillin, the main prophylactic agent, than would die from endocarditis because prophylaxis is withheld, may not be correct since the risks of dying after oral amoxicillin have probably been overestimated. There is a lack of clinical evidence either for or against the efficacy of antibiotic prophylaxis. Unless convincing data is obtained from future research any new international consensus guidelines will continue to be based mainly on expert opinion rather than on good evidence.