Prescribing trends of antibiotics in patients with documented beta-lactam allergy or intolerance

Introduction: According to available literature, approximately 10% of patients will report a penicillin allergy.  Documentation regarding the nature of the allergic reaction is absent in up to 70% of these patient’s medical records. True immediate type reactions must be distinguished from minor reactions or intolerances.  Imprecise allergy documentation is associated with increased antibiotic costs, adverse events, and potential antimicrobial resistance. 

Objectives: The objective of this study is to assess antibiotic prescribing habits in patients with documented beta-lactam allergy or intolerance at a 458 bed community teaching hospital. 

Study Design: Single center, retrospective chart review.

Methods: : A report utilizing the electronic medical record will be used to identify patients who are at least 18 years of age, have a documented beta-lactam allergy, and have received at least one dose of an antibiotic during the study period. Primary study endpoints include: percent of patients with previously documented beta-lactam allergy and corresponding reaction, percent of patients that received a beta-lactam antibiotic with previously documented mild/moderate, severe, or unknown reaction, and percent of patients with a beta-lactam allergy that received an alternative antibiotic. 

Results: A total of 100 patients were included in the study. Seventy-nine percent of patients had a previously documented beta-lactam allergy and corresponding reaction. Approximately 40% of patients that received a beta-lactam antibiotic despite having a previously documented reaction had a mild/moderate reaction, 8% had a severe reaction, and 13% had an unknown reaction. Thirty-nine patients received an alternative antibiotic during their visit.

Conclusions: The results of this study elucidated the complex nature of imprecise allergy documentation. The prescriber’s decision to use a beta-lactam antibiotic is confounded with the poor documentation of allergies. Beta-lactam antibiotics may be tolerated by patients with a documented allergy.