The Penicillin Allergy Delabeling Program: A Multicenter Whole-of-Hospital Health Services Intervention and Comparative Effectiveness Study

Abstract

Background: Penicillin allergies are associated with inferior patient and antimicrobial stewardship outcomes. We implemented a whole-of-hospital program to assess the efficacy of inpatient delabeling for low-risk penicillin allergies in hospitalized inpatients.

Methods: Patients ≥ 18 years of age with a low-risk penicillin allergy were offered a single-dose oral penicillin challenge or direct label removal based on history (direct delabeling). The primary endpoint was the proportion of patients delabeled. Key secondary endpoints were antibiotic utilization pre- (index admission) and post-delabeling (index admission and 90 days).

Results: Between 21 January 2019 and 31 August 2019, we assessed 1791 patients reporting 2315 antibiotic allergies, 1225 with a penicillin allergy. Three hundred fifty-five patients were delabeled: 161 by direct delabeling and 194 via oral penicillin challenge. Ninety-seven percent (194/200) of patients were negative upon oral penicillin challenge. In the delabeled patients, we observed an increase in narrow-spectrum penicillin usage (adjusted odds ratio [OR], 10.51 [95% confidence interval {CI}, 5.39-20.48]), improved appropriate antibiotic prescribing (adjusted OR, 2.13 [95% CI, 1.45-3.13]), and a reduction in restricted antibiotic usage (adjusted OR, 0.38 [95% CI, .27-.54]). In the propensity score analysis, there was an increase in narrow-spectrum penicillins (OR, 10.89 [95% CI, 5.09-23.31]) and β-lactam/β-lactamase inhibitors (OR, 6.68 [95% CI, 3.94-11.35]) and a reduction in restricted antibiotic use (OR, 0.52 [95% CI, .36-.74]) and inappropriate prescriptions (relative risk ratio, 0.43 [95% CI, .26-.72]) in the delabeled group compared with the group who retained their allergy label.

Conclusions: This health services program using a combination of direct delabeling and oral penicillin challenge resulted in significant impacts on the use of preferred antibiotics and appropriate prescribing.

Keywords: antibiotic allergy; antimicrobial stewardship; direct provocation; oral challenge; penicillin allergy.

© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

Figures

Figure 1.

Study profile. Positive oral challenge is defined as an immune or non-immune-mediated reaction following oral penicillin challenge. Negative oral challenge is defined as no reaction following oral penicillin challenge.

Figure 2.

Antibiotic utilization in the delabeled cohort (n = 355). Errors bars represent 95% confidence intervals. aA narrow-spectrum penicillin was defined as 1 of penicillin VK, penicillin G, flucloxacillin, dicloxacillin, ampicillin, or amoxicillin. bAn unrestricted cephalosporin included first- or second-generation cephalosporins. cA restricted cephalosporin included third-generation or later cephalosporins. dA restricted antibiotic included lincosamides (ie, clindamycin, lincomycin), fluoroquinolones (ie, norfloxacin, ciprofloxacin, moxifloxacin), vancomycin, carbapenems (ie, ertapenem, meropenem), and third-generation or later cephalosporins (ie, cefepime, ceftazidime, ceftriaxone). Abbreviations: 90-day, 90-day posttesting admission; BL/BLI, β-lactam/β-lactamase inhibitor; pre, pretesting index admission; post, posttesting index admission.