The high prevalence of labelling of older patients as having an antibiotic allergy is associated with clinicians prescribing alternative antibiotics that are restricted by antimicrobial stewardship programs, according to research published online by the Medical Journal of Australia.

Dr Jason Trubiano and a team of researchers from Austin Health, the University of Melbourne, Monash University and Alfred Health said the implications are that people with antibiotic allergy labels (AALs) are often prescribed broad spectrum antibiotics, such as cephalosporins and fluoroquinolones, that are restricted by antimicrobial stewardship programs.

Many of the allergies in older patients were actually "non-genuine allergies", but rather drug side- effects or intolerances, or the patients were low risk phenotypes, Dr Trubiano and colleagues wrote.

They said AAL prevalence in the general population was previously estimated at 10-20%, but they found a significant burden in their sample of older inpatients. Of 453 inpatients, 24% had an AAL, and a total of 160 AALs were recorded: 34% to simple penicillins, 13% to sulphur antimicrobials, and 11% to cephalosporins.

The authors suggest that re-examining non-recent AALs of general medical inpatients may be "both a high yield and a low risk task."

Eight of the 107 patients with an AAL had, in fact, previously received an antibiotic from the class to which they were believed allergic; none experienced any adverse effects inadvertently re-challenged in this manner.

"If patients had received and tolerated an antibiotic to which they were previously considered allergic, they were more likely to accept a hypothetical re-challenge than those who had not."

The authors concluded that educating clinicians and making changes in the recording of adverse drug reactions by hospitals is required to ensure the accuracy of AALs.

"These findings inform a mandate to assess AALs in the interests of appropriate antibiotic use and drug safety. Prospective studies incorporating AALs into antimicrobial stewardship and clinical practice are required," they wrote.