A novel two-step process for the management of inpatient beta-lactam allergy labels

BACKGROUND:Inpatient beta-lactam allergy labels may increase the unnecessary use of aztreonam and non-beta-lactam antibiotics, which can then lead to more adverse events and increased health care costs, OBJECTIVE: To assess the impact of a novel two-step process (medication history review followed by risk stratification) on rates of beta-lactam delabeling, aztreonam use, and desensitizations on pediatric, adult, and obstetrics inpatients at a tertiary academic center. METHODS:We prospectively collected data on 700 patients who received inpatient consultation from the Beta-Lactam Allergy Evaluation Service from August 2021-July 2022Patients were de-labelled either by medication review alone, drug challenge alone if low-risk history, or penicillin skin test (PST) followed by drug challenge if high-risk history. Generalized linear regression modeling was used to compare aztreonam days of therapy in the intervention year to the two prior years. Drug desensitizations were assessed by electronic chart review. RESULTS:The majority (n=656/700, 94%) of patients had ≥1 beta-lactam allergy label removed, clarified, or both; 77.9% of these patients (n=511/656) had 587 beta-lactam allergy labels removed. Nearly one-third (n=149, 27.6%) had 162 allergy labels removed solely by medication history review. All 114 PST performed were negative, and 98% (8/381) of patients who underwent any drug challenge passed. Only 5.7% of patients de-labelled were re-labelled. There was a 27% reduction in aztreonam use (p=0.007). Beta-lactam desensitizations were reduced by 80%. CONCLUSION:A full-time inpatient beta-lactam allergy service using medication history review and risk stratification can safely and effectively remove inpatient beta-lactam allergy labels, reduce aztreonam use, and decrease beta-lactam desensitizations.