Incidence and nature of adverse reactions to antibiotics used as endocarditis prophylaxis.
OBJECTIVE
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.
Unit of Oral and Maxillofacial Surgery and Medicine, University of Sheffield School of Clinical Dentistry, Claremont Crescent, Sheffield S10 2TA, UK Department of Oral Medicine, Carolinas Medical Center, Charlotte, NC 28203, USA m.thornhill@sheffield.ac.uk.
Martin H
MH
Thornhill
Department of Cardiology, Taunton and Somerset NHS Trust, Taunton, Somerset TA1 5DA, UK.
Mark J
MJ
Dayer
Department of Cardiology, John Radcliffe Hospital, Oxford OX3 9DU, UK.
Bernard
B
Prendergast
Division of Infectious Diseases, Mayo Clinic College of Medicine, Rochester, MN 55905, USA.
Larry M
LM
Baddour
School of Health Sciences, University of Surrey, Guildford, Surrey GU2 7XH, UK.
Simon
S
Jones
Department of Oral Medicine, Carolinas Medical Center, Charlotte, NC 28203, USA.
Peter B
PB
Lockhart
D000658:Amoxicillin / Q000008:administration & dosage / Q000009:adverse effects*; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000009:adverse effects*; D019072:Antibiotic Prophylaxis / Q000009:adverse effects* / Q000379:methods; D002981:Clindamycin / Q000008:administration & dosage / Q000009:adverse effects*; D016360:Clostridioides difficile / Q000302:isolation & purification; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology* / Q000473:pathology*; D004696:Endocarditis / Q000517:prevention & control*; D004739:England / Q000453:epidemiology; D006801:Humans; D015994:Incidence
D000900:Anti-Bacterial Agents; D002981:Clindamycin; D000658:Amoxicillin
adverse drug reactions; amoxicillin; clindamycin; dental