Penicillin Allergy De-labeling Results in Significant Changes in Outpatient Antibiotic Prescribing Patterns.

Thomas Hills,Eamon Duffy,Penny Fitzharris,Nicola Arroll,Janice Capstick,Anthony Jordan

doi:10.3389/falgy.2020.586301

Abstract

Unverified penicillin allergies are common but most patients with a penicillin allergy label can safely use penicillin antibiotics. Penicillin allergy labels are associated with poor clinical outcomes and overuse of second-line antibiotics. There is increasing focus on penicillin allergy “de-labeling” as a tool to improve antibiotic prescribing and antimicrobial stewardship. The effect of outpatient penicillin allergy de-labeling on long-term antibiotic use is uncertain. We performed a retrospective pre- and post- study of antibiotic dispensing patterns, from an electronic dispensing data repository, in patients undergoing penicillin allergy assessment at Auckland City Hospital, New Zealand. Over a mean follow-up of 4.55 years, 215/304 (70.7%) of de-labeled patients were dispensed a penicillin antibiotic. Rates of penicillin antibiotic dispensing were 0.24 (0.18–0.30) penicillin courses per year before de-labeling and 0.80 (0.67–0.93) following de-labeling with a reduction in total antibiotic use from 2.30 (2.06–2.54) to 1.79 (1.59–1.99) antibiotic courses per year. In de-labeled patients, the proportion of antibiotic courses that were penicillin antibiotics increased from 12.81 to 39.62%. Rates of macrolide, cephalosporin, trimethoprim/co-trimoxazole, fluoroquinolone, “other” non-penicillin antibiotic use, and broad-spectrum antibiotic use were all lower following de-labeling. Further, antibiotic costs were lower following de-labeling. In this study, penicillin allergy de-labeling was associated with significant changes in antibiotic dispensing patterns.

Highlights

Penicillin allergy labels (PALs) are common with 8–25% of individuals labeled as allergic to penicillin, depending on the patient group studied [1]
After de-labeling, 70.6% of patients went on to use a penicillin antibiotic over a mean follow up period of 4.55 years
Patients who had their penicillin allergy confirmed had a lower penicillin antibiotic dispensing rate post-assessment, indicating that there may be benefits of undergoing assessment with skin testing and/or an observed penicillin challenge even for patients who are confirmed to be allergic to penicillin

Summary

Introduction

Penicillin allergy labels (PALs) are common with 8–25% of individuals labeled as allergic to penicillin, depending on the patient group studied [1]. Most patients with a PAL will tolerate penicillin antibiotics because these labels are frequently inaccurate. Assessment in a specialist antibiotic allergy clinic with access to penicillin allergy skin testing and observed oral penicillin challenges (drug provocation tests) is a widely-used approach; there is extensive evidence that this is safe and that the majority of patients assessed will tolerate penicillin antibiotics (that is, they are not allergic and can be de-labeled) [3, 12,13,14,15]. Antibiotic allergy assessment and de-labeling meant 59/62 (95.2%) patients were willing to use the de-labeled antibiotic [16]. There is a relative paucity of data on patterns of longerterm antibiotic use in de-labeled patients, in the outpatient setting

Methods

Results

Conclusion