New guidelines with regard to antibiotic prophylaxis for patients at risk of infective endocarditis

Infective endocarditis is a life-threatening disorder that may arise following invasive procedures such as dentistry. UCL research informed 2008 National Institute for Health and Care Excellence guidelines which, when implemented, decreased preventative antibiotic prescriptions for this risk by 78.6%, saving the NHS approximately £4m and reducing fatal anaphylaxis and antibiotic resistance.

Infective endocarditis (IE), an inflammation of the inner tissue of the heart, is a rare disorder but with significant morbidity and mortality. Oral streptococci may cause approximately 48% of confirmed cases of endocarditis. Until 2008, it was standard practice to give antibiotic prophylaxis to at-risk patients prior to certain dental procedures to reduce the risk of IE. While approximately 130,000 per year received antibiotic prophylaxis, there was no strong evidence to support this practice, and some researchers questioned its effectiveness. This uncertainty led to a programme of research at the UCL Eastman Dental Institute (UCL EDI), which began in the late 1990s, to understand the processes involved.

This research provided substantial evidence to challenge the existing guidelines on antibiotic prophylaxis prior to a relevant procedure. In 2008, the National Institute for Health and Care Excellence (NICE) issued Clinical Guideline 64, Prophylaxis against infective endocarditis. The work of UCL EDI was influential in this document and seven papers were cited throughout the document.

The guidelines recommended that antibiotic prophylaxis used solely to prevent IE should not be given to people at risk of IE undergoing dental and non-dental procedures. Four points were highlighted that underpinned this recommendation, of which UCL research supported three:

• there is no consistent association between having an interventional procedure, dental or non-dental, and the development of IE
• regular tooth brushing almost certainly presents a greater risk of IE than a single dental procedure because of repetitive exposure to bacteraemia arising from the oral microbiota
• the clinical effectiveness of antibiotic prophylaxis is not proven.

As a consequence, there has been a demonstrable change in clinical practice, with a resulting decrease in antibiotic prescribing for dental procedures and IE. A review in 2011 revealed that prescriptions in England reduced by 79% in the two years after guidelines were issued with no increase in the rate of IE. A review of dental prescribing in Wales also reported that dental prescriptions decreased sharply after the publication of the NICE guidelines in 2008. Overall this represents a reduction of over half a million doses over a five-year period for the two countries.

The reduction of unnecessary antibiotic prescribing means improved patient safety through reduced adverse reactions to antibiotics; a cost-saving to the NHS through lower wastage; and a reduction in antibiotic use helping to prevent an increase in antibiotic resistance.