Background: In March 2008, the National Institute for Health and Care Excellence recommended stopping antibiotic prophylaxis (AP) for those at risk of infective endocarditis (IE) undergoing dental procedures in the United Kingdom, citing a lack of evidence of efficacy and cost-effectiveness. We have performed a new economic evaluation of AP on the basis of contemporary estimates of efficacy, adverse events, and resource implications. Methods: A decision analytic cost-effectiveness model was used. Health service costs and benefits (measured as quality-adjusted life-years) were estimated. Rates of IE before and after the National Institute for Health and Care Excellence guidance were available to estimate prophylactic efficacy. AP adverse event rates were derived from recent UK data, and resource implications were based on English Hospital Episode Statistics. Results: AP was less costly and more effective than no AP for all patients at risk of IE. The results are sensitive to AP efficacy, but efficacy would have to be substantially lower for AP not to be cost-effective. AP was even more cost-effective in patients at high risk of IE. Only a marginal reduction in annual IE rates (1.44 cases in high-risk and 33 cases in all at-risk patients) would be required for AP to be considered cost-effective at £20 000 ($26 600) per quality-adjusted life-year. Annual cost savings of £5.5 to £8.2 million ($7.3–$10.9 million) and health gains >2600 quality-adjusted life-years could be achieved from reinstating AP in England. Conclusions: AP is cost-effective for preventing IE, particularly in those at high risk. These findings support the cost-effectiveness of guidelines recommending AP use in high-risk individuals.
Incidence and nature of adverse reactions to antibiotics used as endocarditis prophylaxis
Abstract Objectives Antibiotic prophylaxis (AP) administration prior to invasive dental procedures has been a leading focus of infective endocarditis prevention. However, there have been long-standing concerns about the risk of adverse drug reactions as a result of this practice. The objective of this study was to identify the incidence and nature of adverse reactions to amoxicillin and clindamycin prophylaxis to prevent infective endocarditis. Methods We obtained AP prescribing data for England from January 2004 to March 2014 from the NHS Business Services Authority, and adverse drug reaction data from the Medicines and Healthcare Products Regulatory Agency's Yellow Card reporting scheme for prescriptions of the standard AP protocol of a single 3 g oral dose of amoxicillin or a single 600 mg oral dose of clindamycin for those allergic to penicillin. Results The reported adverse drug reaction rate for amoxicillin AP was 0 fatal reactions/million prescriptions (in fact 0 fatal reactions for nearly 3 million prescriptions) and 22.62 non-fatal reactions/million prescriptions. For clindamycin, it was 13 fatal and 149 non-fatal reactions/million prescriptions. Most clindamycin adverse drug reactions were Clostridium difficile infections. Conclusions AP adverse drug reaction reporting rates in England were low, particularly for amoxicillin, and lower than previous estimates. This suggests that amoxicillin AP is comparatively safe for patients without a history of amoxicillin allergy. The use of clindamycin AP was, however, associated with significant rates of fatal and non-fatal adverse drug reactions associated with C. difficile infections. These were higher than expected and similar to those for other doses, durations and routes of clindamycin administration.
Implications of the serine protease HtrA1 in amyloid precursor protein processing
The defining features of the widely conserved HtrA (high temperature requirement) family of serine proteases are the combination of a catalytic protease domain with one or more C-terminal PDZ domains and reversible zymogen activation. Even though HtrAs have previously been implicated in protein quality control and various diseases, including cancer, arthritis, and neuromuscular disorder, the biology of the human family members is not well understood. Our data suggest that HtrA1 is directly involved in the β-amyloid pathway as it degrades various fragments of amyloid precursor protein while an HtrA1 inhibitor causes accumulation of Aβ in astrocyte cell culture supernatants. Furthermore, HtrA1 colocalizes with β-amyloid deposits in human brain samples. Potential implications in Alzheimer's disease are discussed.