IMPACT OF A PHARMACIST-DRIVEN PENICILLIN ALLERGY RE-LABELING PROCESS IN THE EMERGENCY DEPARTMENT SETTINGErin Schuld PharmD, Aayush Patel PharmD, Mckenzie Hodges PharmD
Piedmont Columbus Regional Midtown-Columbus GA
Background/Purpose: Approximately 10% of U.S. patients report a penicillin allergy, yet fewer than 1% are truly allergic. Mislabeling often leads to use of broad-spectrum antibiotics, increasing antimicrobial resistance and risk of adverse effects. Pharmacist-driven allergy clarification protocols may improve antibiotic stewardship by enabling safe re-labeling of inaccurate allergy records. This study evaluates the impact of a pharmacist-driven penicillin allergy re-labeling protocol in the emergency department (ED) using the institution’s hypersensitivity pathway and the Pen-FAST risk stratification tool.
Methods: We conducted a single-center, retrospective chart review of adult patients (≥18 years) presenting to the ED between February 2, 2026 and March 31, 2026 with a documented penicillin allergy. Patients were excluded if they could not meaningfully participate in the allergy assessment for any reason. The primary outcome was the proportion of patients safely and successfully re-labeled using the pharmacist-driven protocol. Secondary outcomes included changes in antibiotic therapy following re-labeling and incidence of adverse reactions during oral or test-dose challenges. Data were abstracted from electronic health records and analyzed using descriptive statistics.
Results: A total of 559 patients were included in this study. 441 patients were not able to have their allergies assessed by a pharmacist. 70 unassessed patients were on antibiotics and, of these, 29 patients potentially could have undergone a change to their antibiotic regimen. 118 patients were able to have their allergy assessed and re-labeled by a pharmacist. 46 assessed patients were receiving antibiotics. Of these 46, 18 patients underwent changes to their antibiotic regimen secondary to the pharmacist assessment. The most frequent change was from a fluoroquinolone, namely levofloxacin, to a cephalosporin with cefepime and ceftriaxone being the most common agents. The second most common change was from aztreonam to a cephalosporin with cefepime and ceftriaxone being the most common agent. 3 challenges (2 amoxicillin and 1 cephalosporin) were performed with no adverse reactions reported.
Conclusion: Implementation of a standardized Pen-FAST-based workflow enabled allergy clarification in a high-acuity setting by a clinical pharmacist. Some patients were able to be successfully transitioned to a first line recommended agent secondary to their allergy assessment, supporting the safety of a pharmacist-driven allergy assessment. While a majority of patients assessed by a pharmacist were not receiving antibiotics, full documentation of the allergy assessment in the electronic medical record may have downstream benefits should antibiotics be required during their next encounter. Overall, a pharmacist-driven penicillin allergy re-labeling process in the ED is feasible, safe, and clinically impactful.
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