Evaluation of a pharmacist-led penicillin allergy de-labelling ward round: a novel antimicrobial stewardship intervention

Adult penicillin allergy programmes in Australian hospitals: a practical guide from the National Antibiotic Allergy Network

Penicillin allergy is a significant burden on patient, prescribing and hospital outcomes. There has been increasing interest in the incorporation of penicillin allergy testing (i.e. delabelling) into antimicrobial stewardship (AMS) programmes to reduce the burden of penicillin allergy labels and improve prescribing. In particular, there has been a focus on point-of-care penicillin allergy assessment and direct oral challenge for low-risk phenotypes. The National Antibiotic Allergy Network has provided a guide to assist AMS clinicians with the incorporation of penicillin allergy programmes, in particular direct oral challenge, into Australian hospitals.

Evaluation of Antibiotic Allergy in the Ambulatory Setting Using a Standardized Questionnaire

Patients are sometimes mislabeled as having an immune-mediated antibiotic allergy in their medical records. Therefore, the aim of this study was to investigate the prevalence of subjects with non-immune mediated reactions to antibiotics using a standardized questionnaire. Subjects aged 18 years and older with a documented antibiotic allergy were identified and recruited from 2 outpatient clinics in the greater Chicago area. Subjects completed a standardized questionnaire during a single visit regarding their previous adverse reaction to an antibiotic. For subjects with multiple documented antibiotic allergies, 1 questionnaire was filled out for each antibiotic allergy. Investigators subsequently evaluated the questionnaire responses to determine whether the adverse reaction was a true immune-mediated allergic reaction or an adverse drug reaction. A total of 98 subjects were recruited with completion of 159 questionnaires. Eighteen subjects (18.37%, 95% CI: 10.7%, 26.3%) had antibiotic allergy labels with no corresponding immune-mediated reaction history. There were 35 allergy labels (22.0%, 95% CI: 14.7%, 29.4%) that were unlikely to be immune-mediated. Antibiotics with the highest percentage of clinical histories that were unlikely to be immune-mediated were macrolides (8 of 11 subjects), nitrofurantoin (1 of 2 subjects), and amoxicillin/clavulanate (2 of 8 subjects). The most common antibiotic allergy labels were penicillin (43 of 159 subjects), sulfonamides (25 of 159 subjects), and fluoroquinolones (21 of 159 subjects). Identification of adverse reactions to antibiotics that are unlikely to be immune-mediated can be accomplished using a standardized questionnaire in the outpatient setting. Improved identification of low-risk antibiotic allergy labels can guide de-labeling initiatives to improve antibiotic prescribing.

Safe Penicillin Allergy Delabeling in Primary Care: A Systematic Review and Meta-Analysis

BACKGROUND

Ten percent of the population is labeled as allergic to penicillin(s), when in fact 90% of these labels are inappropriate. Recent studies have shown that inpatient delabeling by a direct drug challenge (dDC) is safe in low-risk patients. However, there is a need for outpatient and nonallergist delabeling.

OBJECTIVE

To assess the safety of delabeling low-risk adults by means of dDC in primary care.

METHODS

We searched the MEDLINE, Embase, and Cochrane Library databases from inception to March 15, 2022 (updated June 5, 2023) for studies performing dDC in adults in primary care or other outpatient settings. Two researchers independently screened studies for eligibility. The data extraction and critical appraisal were performed by 1 reviewer, and we pooled the results in a meta-analysis.

RESULTS

Of 2138 results, 12 studies (1070 participants) were eligible for inclusion. Three studies evaluated delabeling in primary care and 9 studies in an outpatient hospital setting. There were no critical adverse events during dDC. No reaction occurred in 97.13% of the 1070 patients, who previously labeled as penicillin-allergic, and were safely delabeled. Ten patients (<1%) developed an immediate reaction: 3 had self-limiting reactions and 7 needed antihistaminics, steroids, epinephrine, and/or salbutamol.

CONCLUSIONS

No serious allergic reactions are observed during direct amoxicillin challenge in adults in an outpatient setting. However, with the exception of 1 recent report, these studies are of low to moderate quality. Nonspecialist delabeling is promising, but further research is required on correct risk stratification and safety assessment in large cohort studies evaluating dDC in primary care.

The Safety of Aztreonam Versus Ceftazidime in Patients Labeled With Penicillin Allergy: A Cohort Study

PURPOSE

Penicillin allergy is the most common drug allergy among hospitalized patients. Traditionally, aztreonam is recommended for patients labeled with penicillin allergy (PLWPA) in our institutional empirical antibiotic guidelines. Due to a global aztreonam shortage in December 2022, the antimicrobial stewardship unit recommended ceftazidime as a substitute. There is a paucity of real-world data on the safety profile of ceftazidime in PLWPA. Hence, we evaluated tolerability outcomes of ceftazidime use in PLWPA.

METHODS

This retrospective cohort study compared PLWPA in Singapore General Hospital who received aztreonam (October 2022-December 2022) or ceftazidime (December 2022-February 2023). Patients were stratified according to their risk of allergic reaction (AR) based on history of penicillin allergy. The severity of AR was based on the Delphi study grading system. The primary outcome was development of AR after initiation of aztreonam or ceftazidime. The secondary tolerability outcomes include hepatotoxicity and neurotoxicity.

FINDINGS

There were 168 patients in the study; 69 were men (41.1%) and the median age was 69 years (interquartile range: 59-76 years). Incidence of AR was statistically similar in both arms: 1 of 102 patients (0.98%) in the aztreonam arm vs 2 of 66 patients (3.03%) in the ceftazidime arm (P = 0.33). The patient in the aztreonam arm was deemed at medium risk of having an AR and developed localized rashes (grade 1). Both patients in the ceftazidime arm were deemed at high risk of AR and developed localized skin reaction (grade 1). Hepatotoxicity was observed in 1 patient prescribed aztreonam. No patients in the ceftazidime arm developed adverse events.

IMPLICATIONS

Ceftazidime appears to be better tolerated and cheaper compared with aztreonam in PLWPA, and serves as an antimicrobial stewardship strategy to conserve broader-spectrum antibiotics use.

Current state of education, training and practices in antimicrobial stewardship among pharmacy students: A cross-sectional survey from Kerala, India

PURPOSE

Pharmacists are recognised in guidelines from across the globe as key stakeholders in antimicrobial stewardship (AMS) initiatives. The current study aims to assess the current practices and level of training and education in relation to AMS among pharmacy students from Kerala, India.

METHODS

A cross-sectional web-based survey was developed and disseminated among doctor of pharmacy 5th year students and interns from selected pharmacy colleges across Kerala through key informants. Descriptive statistics were used to analyse the responses.

RESULTS

The response rate was 34.8% (157/450). Whilst the majority of respondents (89.8%, 141/157) recalled being taught about antimicrobial resistance (AMR) as part of the pharmacy curricula, 84.7% (133/157) believed they didn't have sufficient knowledge about AMR. Most of the respondents (64.9%, 102/157) had not received any AMS training. Clinical posting in AMS was the preferred mode of training suggested by most respondents. Respondents who audited antimicrobials as part of their clinical postings (77.9%, 88/113) reported their main responsibility was review of patient records for assessing the appropriateness of antimicrobials (68.2%, 60/88). Inappropriate selection of antimicrobials was the most common error identified by respondents (38.1%, 43/113) and the key method of communicating their recommendation was informing the prescriber in person (46%, 52/113).

CONCLUSION

Whilst pharmacy students are reviewing antimicrobial prescriptions as part of their clinical postings, their education and training in AMR and AMS remain low. The inclusion of practical clinical training for pharmacy students as part of their curricula can be a cost-effective way to promote AMS initiatives.

How to Define and Manage Low-Risk Drug Allergy Labels

Risk stratification in drug allergy implies that specific risk categories (eg, low, moderate, and high) classify historical drug hypersensitivity reactions. These risk categories can be based on reaction phenotypic characteristics, the timing of the reaction and evaluation, the required reaction management, and individual characteristics. Although a multitude of frameworks have been described in the literature, particularly for penicillin allergy labels, there has yet to be a global consensus, and approaches continue to vary between allergy centers. Immune-mediated drug allergies can sometimes be confirmed using skin testing, but a negative drug challenge is required to demonstrate tolerance and remove the allergy from the electronic health record ("delabel" the allergy). Even for quintessential IgE-mediated drug allergy, penicillin allergy, recent data reveal that a direct oral challenge, without prior skin testing, is an appropriate diagnostic strategy in those who are considered low-risk. Drug allergy pathogenesis and clinical manifestations may vary depending on the culprit drug, and as such, the optimal approach should be based on risk stratification that considers individual patient and reaction characteristics, the likely hypersensitivity reaction phenotype, the drug class, and the patient's clinical needs. This article will describe low-risk drug allergy labels, focusing on β-lactam and sulfonamide antibiotics, nonsteroidal anti-inflammatory drugs, iodinated contrast media, and common chemotherapeutics. This review will also address practical management approaches using currently available risk stratification and clinical decision tools.

Impact of penicillin allergy records on antimicrobial prescribing in hospitalised patients

BACKGROUND

The overdiagnosis of penicillin allergy and misclassification of non-truly allergic reactions is a growing public health problem, associated with the overuse of broad-spectrum and restricted antimicrobials. We aimed to evaluate the impact of penicillin allergy status on antimicrobial prescribing.

METHODS

A retrospective study of inpatients with a documented penicillin allergy receiving antimicrobials was conducted from 1 April to 1 July 2021. Antimicrobial prescribing and clinical characteristics were compared between patients with an active penicillin allergy label and those whose label was removed following antimicrobial stewardship team review. Antimicrobials were classified in two categories: i) 'Access' (recommended), ii) 'Watch and Reserve' (restricted) according to WHO AWaRe classification, a tool to guide appropriate antibiotic use.

RESULTS

437 patients with a documented penicillin allergy receiving antimicrobials were included. 353 patients with an active penicillin allergy label, more frequently received antimicrobials from the 'Watch and Reserve list' (283;80% vs 30;37%; p<0.001). In contrast, 84 patients who were de-labelled received more often antimicrobials from the 'Access list' (53;63% vs 64;18%; p<0.001).

CONCLUSIONS

Penicillin allergy reviews and de-labelling strategies may reduce the use of restricted antimicrobials under the 'Watch and Reserve list'. This practice should be encouraged and reinforced in all hospitals.

A multicentre observational study to investigate feasibility of a direct oral penicillin challenge in de-labelling 'low risk' patients with penicillin allergy by non-allergy healthcare professionals (SPACE study): Implications for healthcare systems

OBJECTIVE

The huge burden of inaccurate penicillin allergy labels (PALs) is an important driver of antimicrobial resistance. This is magnified by insufficient allergy specialists and lack of 'point-of-care' tests. We investigated the feasibility of non-allergy healthcare professionals (HCPs) delivering direct oral penicillin challenges (DPCs) for penicillin allergy de-labelling.

METHODS

This prospective observational study was conducted in three hospitals in England across three settings (acute medical, pre-surgical and haematology-oncology). Patients with a PAL were screened and stratified as low risk/high risk. Low risk patients (non-immune mediated symptoms, benign rash, tolerated amoxicillin since and family history) underwent a DPC.

RESULTS

N = 2257 PALs were screened, 1054 were eligible; 643 were approached, 373 declined, 270 consented and 259 risk stratified (low risk = 155; high risk = 104). One hundred and twenty-six low risk patients underwent DPC, 122 (96.8%) were de-labelled with no serious allergic reactions. Conversion rate from screening-to-consent was 12% [3.3% and 17.9% in acute and elective settings respectively; odds ratios for consent were 3.42 (p < 0.001) and 5.53 (p < 0.001) in haematology-oncology and pre-surgical setting respectively. Common reasons for failure to progress in the study included difficulty in reaching patients, clinical instability/medical reasons, lacking capacity to consent and psychological factors.

INTERPRETATION

DPCs can be delivered by non-allergy HCPs. A high proportion of patients with PALs did not progress in the study pathway. Strategies to deliver DPC at optimal points of the care pathway are needed to enhance uptake. Elective settings offer greater opportunities than acute settings for DPC. The safety and simplicity of DPCs lends itself to adoption by healthcare systems beyond the UK, including in resource-limited settings.

EAACI/ENDA position paper on drug provocation testing

In drug hypersensitivity, drug provocation testing (DPT), also called drug challenge, is the gold standard for investigation. In recent years, risk stratification has become an important tool for adjusting the diagnostic strategy to the perceived risk, whilst still maintaining a high level of safety for the patient. Skin tests are recommended before DPT but may be omitted in low-risk patients. The task force suggests a strict definition of such low-risk patients in children and adults. Based on experience and evidence from studies of allergy to beta-lactam antibiotics, an algorithm on how to adjust DPT to the risk, and when to omit skin tests before DPT, is presented. For other antibiotics, non-steroidal anti-inflammatory drugs and other drugs, skin tests are poorly validated and DPT is frequently necessary. We recommend performing DPT with chemotherapeutics and biologicals to avoid unnecessary desensitization procedures and DPT with skin tests negative contrast media. We suggest DPT with anesthetics only in highly specialized centers. Specifics of DPT to proton pump inhibitors, anticonvulsants and corticosteroids are discussed. This position paper provides general recommendations and guidance on optimizing use of DPT, whilst balancing benefits with patient safety and optimizing the use of the limited available resources.

The role of clinical pharmacists in patients with suspected allergy to β-lactams: A systematic review

OBJECTIVE

To analyze the role played by the clinical pharmacist and its impact in antibiotic stewardship facing suspected allergy to beta-lactam antibiotics.

METHOD

We performed two different independent bibliographic searches. A total of 35 articles were found, and the final number included in the study was 12. We analysed the articles and collected variables of efficacy, safety and applicability of evaluation tools applied to patients with suspected allergy to beta-lactams. Also, the variation in the consumption and prescription profile of alternative antibiotics was analyzed.

RESULTS

The selected studies analysed questionnaires, allergy delabeling, intradermal tests and oral challenge tests performed by pharmacists. Significant differences in the efficacy endpoint were found in 4 studies in favour of pharmaceutical intervention. In the study of Kwiatkowski et al, cefazolin use increased in surgical patients after pharmacist intervention (65 vs. 28%; p < 0.01). In a quasi-experimental study, the mean defined daily dose of aztreonam and the mean days of therapy per 1000 patients/day decreased (21.23 vs 9.05, p <0.01) and (8.79-4.24, p = 0.016), pre and post-intervention, respectively, increasing antibiotic de-escalations (p ≤ 0.01). In another quasi-experimental study, the prescription of restricted-use antibiotics decreased (42.5% vs. 17.9%, p < 0.01) and the use of pre-surgical prophylactic antibiotics alternative to cefazolin (81.9% vs 55.9%, p<0.01) in another study. Other study showed that the mean time per interview was 5.2 minutes per patient. No adverse events were reported in any study.

CONCLUSION

The pharmacist intervention in the evaluation of the patient with suspected allergy to beta-lactams is effective, safe and feasible to implement on daily clinical practice. The standardization of protocols to clarify the history of allergies and development of evaluation tools represent simple screenings to perform delabelling or refer to the Immunoallergology service, improving penicilins use and reducing the need for second line antibiotics. More studies are needed to standardize the desensitization tests made by pharmacists. However, despite these results, the involvement and leadership of the pharmacist in this area is limited and constitutes a future challenge for the profession.

Low-risk penicillin allergy delabeling: a scoping review of direct oral challenge practice, implementation, and multi-disciplinary approaches

INTRODUCTION

Penicillin allergy is common, and there is increased clinician interest in direct oral challenge (DOC) as a testing strategy for low-risk penicillin allergy. To aid wider implementation of DOC, consensus definitions of low-risk penicillin allergy phenotypes, and standardized approaches to assessment, DOC procedures, and evaluation, are required.

AREAS COVERED

This review systematically reviews studies that have utilized penicillin DOC in healthcare settings to identify heterogeneity in implementation approaches and synthesize low-risk definitions, procedures, and evaluation.

EXPERT OPINION

Opportunity exists to standardize penicillin DOC procedures in patients with a low-risk penicillin allergy to optimize antimicrobial prescribing and reduce the burden of penicillin allergy. Standardizing the definitions of 'low-risk' and 'positive challenge,' and improving the evaluation of patient safety, alongside the development of a unified approach to the structure of undertaking an oral challenge, is likely to increase uptake and confidence among non-allergist clinicians.

[Translated article] The role of clinical pharmacists in patients with suspected allergy to β-lactams: A systematic review

OBJECTIVE

To analyze the role played by the clinical pharmacist and its impact in antibiotic stewardship facing suspected allergy to beta-lactam antibiotics.

METHOD

We performed 2 different independent bibliographic searches. A total of 35 articles were found, and the final number included in the study was 12. We analyzed the articles and collected variables of efficacy, safety, and applicability of evaluation tools applied to patients with suspected allergy to beta-lactams. Also, the variation in the consumption and prescription profile of alternative antibiotics was analyzed.

RESULTS

The selected studies analyzed questionnaires, allergy delabeling, intradermal tests, and oral challenge tests performed by pharmacists. Significant differences in the efficacy endpoint were found in 4 studies in favor of pharmaceutical intervention. In the study of Kwiatkowski et al., cefazolin use increased in surgical patients after pharmacist intervention (65% vs 28%; P < .01). In a quasi-experimental study, the mean defined daily dose of aztreonam and the mean days of therapy per 1000 patients/day decreased (21.23 vs 9.05, P <.01) and (8.79-4.24, P = .016), pre- and post-intervention, respectively, increasing antibiotic de-escalations (P = < .01). In another quasi-experimental study, the prescription of restricted use antibiotics decreased (42.5% vs 17.9%, P < .01)and the use of pre-surgical prophylactic antibiotics alternative to cefazolin (81.9% vs 55.9%, P < .01)in another study. Other study showed that the mean time per interview was 5.2 min per patient. No adverse events were reported in any study.

CONCLUSION

The pharmacist intervention in the evaluation of the patient with suspected allergy to beta-lactams is effective, safe, and feasible to implement on daily clinical practice. The standardization of protocols to clarify the history of allergies and development of evaluation tools represent simple screenings to perform delabeling or refer to the Immunoallergology service, improving penicilins use and reducing the need for second-line antibiotics. More studies are needed to standardize the desensitization tests made by pharmacists. However, despite these results, the involvement and leadership of the pharmacist in this area is limited and constitutes a future challenge for the profession.

Ethics of antibiotic allergy

Antibiotic allergies are commonly reported among patients, but most do not experience reactions on rechallenge with the same agents. These reported allergies complicate management of infections in patients labelled as having penicillin allergy, including serious infections where penicillin-based antibiotics are the first-line (most effective and least toxic) treatment option. Allergy labels are rarely questioned in clinical practice, with many clinicians opting for inferior second-line antibiotics to avoid a perceived risk of allergy. Reported allergies thereby can have significant impacts on patients and public health, and present major ethical challenges. Antibiotic allergy testing has been described as a strategy to circumvent this dilemma, but it carries limitations that often make it less feasible in patients with acute infections or in community settings that lack access to allergy testing. This article provides an empirically informed ethical analysis of key considerations in this clinical dilemma, using Staphylococcus aureus bacteraemia in patients with penicillin allergies as a case study. We argue that prescribing first-line penicillin-based antibiotics to patients with reported allergies may often present a more favourable ratio of benefits to risks, and may therefore be more ethically appropriate than using second-line drugs. We recommend changes to policy-making, clinical research and medical education, in order to promote more ethically acceptable responses to antibiotic allergies than the status quo.

Penicillin allergy de-labelling by non-allergists: a comparison of testing protocols

Optimizing penicillin allergy de-labelling (PADL) to ensure patients with an incorrect penicillin allergy record are de-labelled with minimal patient harm is important for antibiotic stewardship. The heterogeneity of inclusion and exclusion criteria in the published penicillin allergy testing protocols risks suboptimal delivery of PADL. We compared the similarities and the differences between non-allergist-delivered PADL testing protocols and make suggestions for harmonization. The observed variation in testing practice has two broad elements: (i) definitions and terminology; and (ii) differences in the acceptability of perceived risk. All direct drug provocation testing (DDPT) protocols included patients with benign delayed rash as eligible for testing, although the remoteness of the rash, and the terminology used to describe the rash, differed. Patients with features of potential IgE reactions were excluded from most DDPT protocols, but not all of them. There was differing advice on how to manage patients who had subsequently tolerated penicillin since the index reaction and differences in which patients were considered ineligible for DDPT due to acuity of illness, comorbidities and concomitant medications. Standardization of the terminology used in penicillin allergy testing protocols and consensus on inclusion and exclusion criteria are required for safe and efficient PADL delivery at scale by non-allergists.

Penicillin Allergy Impact and Management

There is international evidence that penicillin allergies are associated with inferior prescribing and patient outcomes. A host of tools now exist from assessment (risk assessment tools, clinical decision rules) to delabeling (the removal of a beta-lactam allergy via testing or medical reconciliation) to reduce the impact of these "labels" in the hospital and community setting, as a primary antimicrobial stewardship intervention.

[Antibiotic allergies: targeted approach in suspected β‑lactam allergy]

Allergic reactions to antibiotics belong to hypersensitivity drug reactions and can trigger both immunoglobulin E-mediated symptoms and T cell-mediated symptoms. Skin manifestations are the most common symptoms. Although reporting a penicillin allergy results in considerable restrictions in the treatment of acute infections, which may be associated with poor treatment outcomes, in most cases the label 'penicillin allergy' is not called into question or critically reviewed. However, in 85-90% of patients, 'penicillin allergy' constitutes a mislabeling of a non-specific intolerance reaction that does not pose a risk to the patient when re-exposed to penicillins. Careful history taking, an evaluation of manifestations in the past, and easy-to-perform initial diagnostic steps are crucial in differentiating non-specific intolerance reactions from penicillin allergy sensu stricto. Thus, a penicillin de-labeling strategy allows for optimized antibiotic therapy in the event of a future infection. Although allergic cross-reactivity between different β‑lactam antibiotics can occur, the risk for a severe cross-reactivity is dependent on chemical properties of the specific β‑lactam. Published cross-reactivity tables can help in risk stratification and choice of alternative β‑lactam agents.

A pharmacist-led penicillin allergy de-labelling project within a preoperative assessment clinic: the low-hanging fruit is within reach

BACKGROUND

Having a false penicillin-allergy label is linked to longer hospital stays and to an increased risk of Clostridioides difficile and meticillin-resistant Staphylococcus aureus infection.

AIM

To assess a penicillin-allergy de-labelling tool designed for use by the non-allergist.

METHODS

Patients attending the surgical preoperative assessment clinic (POAC) at a large UK teaching hospital, who reported a penicillin allergy, were directly de-labelled by nursing or pharmacy staff, where appropriate. A penicillin-allergy de-labelling tool designed for use by the non-allergist was adapted and applied; nursing staff were provided with supporting information and education to enable removal of spurious labels. Antimicrobial pharmacists (AMPs) provided follow-up, cross-checked prophylactic antibiotics administered, interrogated clinical notes, and telephoned patients following their surgery, for details of any adverse reactions suffered.

FINDINGS

A total of 163 patients reporting a penicillin allergy were identified for intervention. Twenty-nine (17.8%) patients reported a penicillin-allergy history appropriate for direct de-labelling, of whom eight (27.6%) declined to consent. The remaining 21 patients (12.8%) were directly de-labelled, with 12 (7.4%) patients consenting during their POAC appointment; the remaining nine (5.5%) patients were consented and de-labelled after their surgery by an AMP.

CONCLUSION

The POAC was identified as an appropriate location and time-point in the patient pathway to enable the direct removal of spurious penicillin-allergy labels prior to surgery. Results suggest that this could be undertaken by nursing staff, although support from AMPs enabled a greater number of patients to be de-labelled.

Impact of an Inpatient Allergy Guideline on β-Lactam and Alternative Antibiotic Use

BACKGROUND

A guideline identifying when inpatients with penicillin or cephalosporin antibiotic allergy labels (PCAAL) can receive β-lactam antibiotics increased β-lactam receipt at a large northeastern US health care system.

OBJECTIVE

To report outcomes of implementing a similar guideline and electronic order set (OS) at an independent academic health care system.

METHODS

Penicillin/cephalosporin receipt (percentage of inpatients receiving full doses) and alternative antibiotic use (days of therapy per 1000 patient-days [DOT/1000PD]) were compared over 3 periods before (February 1, 2017, to January 31, 2018) and after guideline implementation (February 1, 2018, to January 31, 2019), and after OS implementation (February 1, 2019, to January 31, 2020) among inpatients with PCAAL admitted on medical services with access to guideline/OS and education (Medical-PCAAL, n = 8721), surgical services with access to guideline/OS without education (Surgical-PCAAL, n = 5069), and obstetrics/gynecology services without interventions (Ob/Gyn-PCAAL, n = 798) and inpatients without PCAAL admitted on the same services (Medical-No-PCAAL, n = 50,840; Surgical-No-PCAAL, n = 29,845; Ob/Gyn-No-PCAAL, n = 6109). χ2 tests were used to compare categorical variables, and analysis of variance was used to compare continuous and interrupted time series analyses (ITSA) to investigate the guideline/OS implementation effect on penicillin/cephalosporin receipt.

RESULTS

In the Medical-PCAAL group, penicillin/cephalosporin receipt increased (58%-68%, P < .001), specifically for cefazolin (8%-11%, P = .02) and third- to fifth-generation cephalosporins (43%-48%, P = .04), and aztreonam use decreased (12 DOT/1000PD, P = .03). In the Medical-No-PCAAL group, penicillin/cephalosporin receipt increased (88%-90%, P = .004), specifically for penicillin (40%-44%, P < .001), without changes in aztreonam use. Significant changes were not observed in these outcomes on surgical or obstetrics/gynecology services. Per ITSA, guideline/OS implementation was associated with increased penicillin/cephalosporin receipt in the Medical-PCAAL group only.

CONCLUSION

Guideline and OS implementation was associated with improved antibiotic stewardship on inpatient services that also received allergy education.

The Who, What, When, and Where of Inpatient Direct Oral Penicillin Challenge-Implications for Health Services Implementation

Inpatient direct oral challenge programs are increasingly deployed as part of antimicrobial stewardship initiatives to reduce the burden and impacts of penicillin allergy labels on antibiotic prescribing. Using data from a prospective, multicenter cohort inpatient penicillin allergy program, we identify the key targets for delabeling to aid health service implementation.

Delabeling of Penicillin Allergy: Room for Improvement

BACKGROUND

Penicillin allergy labels have been shown to be associated with suboptimal treatment, negative health outcomes, and increased antibiotic resistance. Many inpatients claim to have penicillin allergy, but studies show that allergy can be disproved and the label removed in up to 90% of cases.

OBJECTIVES

The purpose of the study was to investigate the proportion of patients with a penicillin allergy label in a Danish hospital and to classify patients according to the risk of having penicillin allergy in "no risk," low, and high risk.

METHODS

For 22 days, inpatients with penicillin allergy labels were interviewed, had their dispensed penicillin prescriptions examined, and were subsequently categorized into risk groups based on the risk evaluation criteria in national guidelines.

RESULTS

In total, 260 patients had a penicillin allergy label (10% of the inpatients). Out of 151 included patients, 25 were "no risk" patients (17%), who could potentially have their penicillin allergy label removed without testing. 42 were low-risk patients (28%). 10 "no risk" patients and 20 low-risk patients had been prescribed and dispensed one or more penicillins despite an allergy label.

CONCLUSION

Ten percent of inpatients have a penicillin allergy label in a Danish hospital. 17% of these could potentially have their penicillin allergy label removed without allergy testing.

Penicillin de-labelling in vancouver, British Columbia, Canada: comparison of approaches, outcomes and future directions

BACKGROUND

Inaccurate penicillin allergy labels lead to inappropriate antibiotic prescriptions and harmful patient consequences. System-wide efforts are needed to remove incorrect penicillin allergy labels, but more health services research is required on how to best deliver these services.

METHODS

Data was extracted from five hospitals in Vancouver, British Columbia, Canada from October 2018-May 2022. The primary outcomes of this study were to outline de-labelling protocol designs, identify the roles of various healthcare professionals in de-labelling protocols and identify rates of de-labelling penicillin allergies and associated adverse events at various institutions. Our secondary outcome was to describe de-labelling rates for special populations, including pediatric, obstetric and immunocompromised subpopulations. To achieve these outcomes, participating institutions provided their de-labelling protocol designs and data on program participants. Protocols were then compared to find common themes and differences. Furthermore, adverse events were reviewed and percentages of patients de-labelled at each institution and in total were calculated.

RESULTS

Protocols demonstrated a high level of variability, including different methods of participant identification, risk-stratification and roles of providers. All protocols used oral and direct oral challenges, heavily involved pharmacists and had physician oversight. Despite the differences, of the 711 patients enrolled in all programs, 697 (98.0%) were de-labelled. There were 9 adverse events (1.3%) with oral challenges with mainly minor symptoms.

CONCLUSIONS

Our data demonstrates that de-labelling programs effectively and safely remove penicillin allergy labels, including pediatric, obstetric and immunocompromised patients. Consistent with current literature, most patients with a penicillin allergy label are not allergic. De-labelling programs could benefit from increasing clinician engagement by increasing accessibility of resources to providers, including guidance for de-labelling of special populations.

[Antibiotic allergies: targeted approach in suspected β‑lactam allergy]

Allergic reactions to antibiotics belong to hypersensitivity drug reactions and can trigger both immunoglobulin E-mediated symptoms and T cell-mediated symptoms. Skin manifestations are the most common symptoms. Although reporting a penicillin allergy results in considerable restrictions in the treatment of acute infections, which may be associated with poor treatment outcomes, in most cases the label 'penicillin allergy' is not called into question or critically reviewed. However, in 85-90% of patients, 'penicillin allergy' constitutes a mislabeling of a non-specific intolerance reaction that does not pose a risk to the patient when re-exposed to penicillins. Careful history taking, an evaluation of manifestations in the past, and easy-to-perform initial diagnostic steps are crucial in differentiating non-specific intolerance reactions from penicillin allergy sensu stricto. Thus, a penicillin de-labeling strategy allows for optimized antibiotic therapy in the event of a future infection. Although allergic cross-reactivity between different β‑lactam antibiotics can occur, the risk for a severe cross-reactivity is dependent on chemical properties of the specific β‑lactam. Published cross-reactivity tables can help in risk stratification and choice of alternative β‑lactam agents.

The effectiveness of interventions that support penicillin allergy assessment and delabeling of adult and pediatric patients by nonallergy specialists: a systematic review and meta-analysis

OBJECTIVES

Penicillin allergy records are often incorrect and may result in harm. We aimed to systematically review the effectiveness and safety of nonallergist health care worker delivery of penicillin allergy delabeling.

METHODS

We searched EMBASE/MEDLINE/CINAHL (Ovid), PsycInfo, Web of Science, and Cochrane CENTRAL from inception to January 21, 2022 and unpublished studies and gray literature. The proportion of patients allergic to penicillin delabeled and harmed was calculated using random-effects models.

RESULTS

Overall, 5019 patients were delabeled. Using allergy history alone, 14% (95% confidence interval [CI], 9-21%) of 4350 assessed patients were delabeled without reported harm. Direct drug provocation testing resulted in delabeling in 27% (95% CI, 18-37%) of 4207 assessed patients. Of the 1373 patients tested, 98% were delabeled (95% CI, 97-99%), and nonserious harm was reported in 1% (95% CI, 0-2%). Using skin testing, followed by drug provocation testing, 41% (95% CI, 24-59%) of 2890 assessed patients were delabeled. Of the 1294 tested patients, 95.0% (95% CI, 90-99%) were delabeled, and the reported harm was low (0%; (95% CI 0-1%).

CONCLUSION

Penicillin allergy delabeling by nonallergists is efficacious and safe. The proportion of assessed patients who can be delabeled increases with the complexity of testing method, but substantial numbers can be delabeled without skin testing.

Study protocol for PREPARE: a phase II feasibility/safety randomised controlled trial on PeRiopErative Penicillin AlleRgy TEsting

INTRODUCTION

Patient-reported antibiotic allergy labels (AALs) are common. These labels have been demonstrated to have a negative impact on use of appropriate antibiotics and patient-related health outcomes. These patients are more likely to receive suboptimal antibiotics, have increased rates of surgical site infections and are more likely to be colonised with multidrug-resistant organisms. Increasing recognition that antibiotic allergy forms a key part of good antimicrobial stewardship has led to calls for greater access to antibiotic allergy assessment.PREPARE is a pilot randomised controlled trial of beta-lactam allergy assessment and point of care delabelling in perioperative patients utilising a validated antibiotic allergy assessment tool that has been repurposed into a smartphone application. The aim of the study is to assess the feasibility and safety of this approach in the perioperative outpatient setting.

METHODS AND ANALYSIS

Adult participants requiring elective surgery and are likely to require prophylactic intravenous antibiotics will be recruited. During the intervention phase, participants will be randomised to the intervention or control arm, with control patients receiving usual standard of care. Those randomised to intervention undertake a risk assessment via the smartphone application, with those deemed low risk proceeding to direct oral provocation with either a penicillin or cephalosporin. Study outcomes will be evaluated in the postintervention phase, 30 and 90 days after surgery.Feasibility of intervention delivery and recruitment will be reported as proportions with respective 95% CIs. Participants who experience an antibiotic adverse event will be reported by group with respective 95% CIs and compared using modified Poisson regression model with robust SE estimation.

ETHICS AND DISSEMINATION

This protocol has received approval from the Austin Health human research and ethics committee, Heidelberg, Victoria, Australia (HREC/17/Austin/575). Results will be disseminated via publication in peer-reviewed journals as well as presentation at international conferences.

TRIAL REGISTRATION NUMBER

ACTRN12620001295932.

Comparative Effectiveness, Safety, and Real-World Outcomes of a Nurse-Led, Protocol-Driven Penicillin Allergy Evaluation From the Hong Kong Drug Allergy Delabelling Initiative (HK-DADI)

BACKGROUND

There is a high prevalence of unconfirmed penicillin allergy, which is associated with a multitude of adverse clinical outcomes. With the overwhelming burden of currently incorrect labels and the lack of allergy specialist services, new delabeling strategies are urgently needed.

OBJECTIVE

To assess the effectiveness, safety, and real-world outcomes of a nurse-led, protocol-driven evaluation of penicillin allergy, the Hong Kong Drug Allergy Delabelling Initiative (HK-DADI).

METHODS

Adult patients with suspected penicillin allergy were recruited into HK-DADI. Allergy and postdelabeling outcomes were retrospectively compared between patients evaluated via HK-DADI or traditional allergist evaluation.

RESULTS

A total of 312 completed penicillin allergy evaluation: 84 (27%) and 228 (73%) via HK-DADI and traditional pathways, respectively. Overall, 280 penicillin allergies were delabeled (90%). The delabeling rate between HK-DADI and traditional pathways was similar (90% vs 89%; P = .796). Among patients of the HK-DADI pathway, the delabeling rate was significantly higher among low-risk (LR) compared with non-LR patients (97% vs 77%; P = .010). Skin tests did not add diagnostic value among LR patients. No patients developed severe or systemic reactions during the evaluation. Upon 6- to 12-month follow-up (median, 10 months), 123 patients experienced infective episodes (44%) and 63 used penicillins again after delabeling (23%). This proportion was significantly higher in patients who were delabeled via HK-DADI compared with the traditional pathway (32% vs 19%; P = .026).

CONCLUSIONS

The Hong Kong Drug Allergy Delabelling Initiative, a nurse-led, protocol-driven evaluation, was safe and effective in penicillin allergy delabeling. It led to an even higher rate of future penicillin use after delabeling and mitigated the need for unnecessary skin testing among LR patients.

Penicillin Allergy Delabeling Program: an exploratory economic evaluation in the Australian context

BACKGROUND

Internationally, clinical and economic advantages of low-risk penicillin delabelling have been explored, supporting changes to healthcare delivery systems where penicillin delabelling is embedded into inpatient usual care.

AIMS

To determine if economic advantages of low-risk inpatient penicillin delabelling, described in the international literature, are realised in the Australian context.

METHODS

This explorative economic evaluation had prospective patient data collection between January and August 2019, across two Australian health services. Part 1: determine the cost per effectively delabelled patient for Penicillin Allergy Delabeling Program inpatients (PADP cohort) compared with Outpatient Antibiotic Allergy Testing Service outpatients (OAATS cohort). Part 2: a cost analysis to compare hospital costs for inpatients with low-risk penicillin allergy who did (PADP cohort) and did not (usual care cohort) undergo PADP delabelling.

RESULTS

Part 1: the PADP (n = 350) and OAATS (n = 27 patients, n = 36 individual visits) cohorts were comparable. In PADP, costs/proportion delabelled was $20.10/0.98, equating to $20.51 per effectively delabelled patient; in OAATS, it was $181.24/0.50, equating to $362. Compared with OAATS, PADP was associated with savings of $341.97 per effectively delabelled patient, indicating the outpatient testing was the dominated strategy, being more costly and less effective. Part 2: the PADP (n = 218) and usual care (n = 32) cohorts were comparable. Significantly favouring the delabelled PADP cohort, the mean difference per patient was -4.41 days (95% confidence interval: -7.64, -1.18) and -$9467.72 (95% confidence interval: -$15 419.98, -$3515.46).

CONCLUSIONS

Consistent with international literature, delabelling low-risk penicillin allergies in the inpatient setting had economic advantages in the Australian context. Fully powered economic evaluations are urgently required to consolidate these findings.

Barriers to paediatric penicillin allergy de-labelling in UK secondary care: a regional survey

BACKGROUND

Incorrect penicillin allergy labels result in the use of inappropriately broad-spectrum antibiotics. De-labelling inaccurate penicillin allergy promotes antimicrobial stewardship and optimises prescribing practices. The objectives were to evaluate paediatric clinicians' knowledge and understanding of penicillin allergy and to identify barriers in tackling incorrect penicillin allergy labels.

METHODS

Paediatric clinicians from across the West Midlands of the UK were surveyed using an online, anonymised questionnaire between 1 August and 30 September 2021. Domains explored were (1) approach to penicillin allergy clinical vignettes, (2) knowledge of the impact of penicillin allergy labels, (3) frequency of allergy-focused history questions and (4) barriers in tackling incorrect penicillin allergy.

RESULTS

Responses were received from 307 paediatric clinicians across 12 hospitals. Sixty-one per cent would not prescribe a penicillin-based antibiotic if a family history of penicillin allergy was reported. There was an overall deficit in taking an allergy-focused history with only 36.5% inquiring about diagnostic confirmation. Absence, or lack of awareness of a referral pathway for antibiotic allergy evaluation (58.6%) and unfamiliarity of the indications for oral provocation testing (55%) were the most common reported barriers to penicillin allergy de-labelling. Fifty-one per cent would rather 'play it safe' than explore penicillin allergy confirmation as it is felt that alternative treatments were readily available.

CONCLUSIONS

The deficiency in antibiotic allergy-focused history among paediatric clinicians highlights the need for better allergy education across all clinical grades. Pragmatic algorithms and clear referral pathways could address barriers faced by non-allergists in de-labelling incorrect penicillin allergy.

Improving drug allergy label accuracy by supervised safety- and protocol-driven evaluation

Introduction: Drug allergies are often self-reported but of unknown accuracy. We carried out a prospective study to examine the utility and safety of formal allergology evaluation, and to identify factors associated with accurate drug allergy labels. Method: All patients who underwent drug allergy evaluation in our clinic during the study period were recruited. Baseline demographics, characteristics of index hypersensitivity reaction and outcomes of evaluation were recorded. Results: A total of 331 patients from March 2019 to June 2021 completed drug allergy evaluation to index drugs of concern. There were 123 (37%) male patients, and the mean age was 49 years (standard deviation 17). There were 170 beta-lactam antibiotics, 53 peri-operative drugs, 43 others, 38 non-steroidal anti-inflammatory drugs, and 27 non-beta-lactam antibiotic evaluations. Index reaction occurred within 5 years in 165 (50%) patients, with latency of less than 4 hours in 125 (38%) patients. The most common index reactions were rash, angioedema and urticaria. There were 57 (17%) evaluations stratified as low risk, 222 (67%) moderate risk, and 52 (16%) high risk based on multidisciplinary consensus. Allergy label was found to be false (negative drug evaluation) in 248 (75%) patients, while 16/237 (7%) skin tests, 44/331 (13%) in-clinic graded challenge, and 23/134 (17%) home prolonged challenges were positive (true drug allergy). The most common evaluation reactions were rash and urticaria. No cases of anaphylaxis were elicited. Conclusion: Seventy-five percent of drug allergy labels are inaccurate. Risk-stratified, protocolised allergy evaluation is safe. Prolonged drug challenge increases the sensitivity of drug allergy evaluation and should therefore be performed when indicated. Keywords: Drug allergy, drug hypersensitivity, graded challenge, prolonged drug provocation, skin testing

Differences in beta-lactam and penicillin allergy: Beyond the West and focusing on Asia-Pacific

Beta-lactam (BL) antibiotic "allergy" labels are common, but often overdiagnosed. Although much research has been focused on the BL allergy and the delabelling process in the West, studies from other parts of the world remain sparse. This review outlines the contrasting global epidemiology, shifting clinical practices and disparities of BL allergy in the Asia-Pacific region compared with the West. Innovative strategies to overcome barriers in BL allergy workup are discussed and potential directions for future research and service development are also proposed.

The role of the clinical pharmacist in antimicrobial stewardship in Asia: A review

Clinical pharmacist-driven antimicrobial stewardship programs (ASPs) have been successfully implemented. Although relevant guidance and several studies suggest that clinical pharmacists be integrated into the current ASP team model, barriers still exist in Asia, primarily due to lack of dedicated personnel and lack of career advancement. We review the effectiveness and the ideal role of clinical pharmacist among ASPs in Asia. Several studies conducted in Asia have shown the effectiveness of pharmacist-led ASP interventions in hospitals and other healthcare settings. However, opportunities to expand the role of clinical pharmacists in ASPs in Asia exist in the implementation of rapid diagnostic test and drug allergies.

Antimicrobial stewardship in solid organ transplant recipients: Current challenges and proposed metrics

BACKGROUND

Solid organ transplant (SOT) recipients are challenging populations for antimicrobial stewardship interventions due to a variety of reasons, including immunosuppression, consequent risk of opportunistic and donor-derived infections, high rates of infection with multi-drug resistant organisms (MDROs), Clostridioides difficile, and need for prolonged antimicrobial prophylaxis. Despite this, data on stewardship interventions and metrics that address the distinct needs of these patients are limited.

METHODS

We performed a narrative review of the current state of antimicrobial stewardship in SOT recipients, existing interventions and metrics in this population, and considerations for implementation of transplant-specific stewardship programs.

RESULTS

Antimicrobial stewardship metrics are evolving even in the general patient population. Data on metrics applicable to the SOT population are even more limited. Standard process, outcomes, and balancing metrics may not always apply to the SOT population. A successful stewardship program for SOT recipients requires reviewing existing data, applying general stewardship principles, and understanding the nuances of SOT patients.

CONCLUSION

As antimicrobial stewardship interventions are being implemented in SOT recipients; new metrics are needed to assess their impact. In conclusion, SOT patients present a challenging but important opportunity for antimicrobial stewards.

ABBREVIATIONS

SOT, antimicrobial stewardship program, MDRO, Clostridioides difficile infection, Centers for Disease Control and Prevention, Infectious Diseases Society of America, prospective audit and feedback, hematopoietic cell transplant, cytomegalovirus, trimethoprim-sulfamethoxazole, surgical site infections, nucleic acid amplification testing, days of therapy, defined daily dose, and length of stay.

Standards for practical intravenous rapid drug desensitization & delabeling: A WAO committee statement

Drug hypersensitivity reactions (DHRs) to intravenous drugs can be severe and might leave patients and doctors in a difficult position where an essential treatment or intervention has to be suspended. Even if virtually any intravenous medication can potentially trigger a life-threatening DHR, chemotherapeutics, biologics, and antibiotics are amongst the intravenous drugs most frequently involved in these reactions. Admittedly, suspending such treatments may negatively impact the survival outcomes or the quality of life of affected patients. Delabeling pathways and rapid drug desensitization (RDD) can help reactive patients stay on first-choice therapies instead of turning to less efficacious, less cost-effective, or more toxic alternatives. However, these are high-complexity and high-risk techniques, which usually need expert teams and allergy-specific techniques (skin testing, in vitro testing, drug provocation testing) to ensure safety, an accurate diagnosis, and personalized management. Unfortunately, there are significant inequalities within and among countries in access to allergy departments with the necessary expertise and resources to offer these techniques and tackle these DHRs optimally. The main objective of this consensus document is to create a great benefit for patients worldwide by aiding allergists to expand the scope of their practice and support them with evidence, data, and experience from leading groups from around the globe. This statement of the Drug Hypersensitivity Committee of the World Allergy Organization (WAO) aims to be a comprehensive practical guide on the technical aspects of implementing acute-onset intravenous hypersensitivity delabeling and RDD for a wide range of drugs. Thus, the manuscript does not only focus on clinical pathways. Instead, it also provides guidance on topics usually left unaddressed, namely, internal validation, continuous quality improvement, creating a healthy multidisciplinary environment, and redesigning care (including a specific supplemental section on a real-life example of how to design a dedicated space that can combine basic and complex diagnostic and therapeutic techniques in allergy).

Drug Allergy Delabeling Programs: Recent Strategies and Targeted Populations

Drug allergy delabeling programs have become an essential element of antibiotic stewardship. Development of delabeling programs involves careful selection of target patient population, thoughtful design of delabeling approach, stakeholder engagement, assembly of key team members, implementation, and evaluation of clinical and safety outcomes. Recent programs have targeted patients thought to be most likely to benefit from removal of inaccurate antibiotic allergy labels, those with β-lactam antibiotic allergies and high-risk populations likely to need β-lactam antibiotics as first-line treatment. This review provides an overview of current risk stratification methods and β-lactam cross-reactivity data and summarizes how different inpatient and outpatient delabeling programs have used these concepts in delabeling algorithms. β-Lactam delabeling programs for inpatients, pediatric patients, and programs utilizing telehealth have been implemented with good outcomes. This review also focuses on delabeling programs for high-risk populations likely to benefit from first-line β-lactam antibiotics. These populations include perioperative, prenatal, and immunocompromised patients. Delabeling programs have been successful in the inpatient and outpatient settings at enabling appropriate antibiotic use. This article reviews delabeling strategies utilized by these programs with a focus on highlighting elements key to their success and future areas for innovation.

Hospital Pharmacists and Antimicrobial Stewardship: A Qualitative Analysis

Antimicrobial stewardship programmes (ASPs) in hospitals are predominantly led by specific ASP physicians and pharmacists. Limited studies have been conducted to appreciate non-ASP-trained hospital pharmacists' perspectives on their roles in antimicrobial stewardship. Focus group discussions (FGDs) were conducted with 74 pharmacists, purposively sampled from the 3 largest acute-care public hospitals in Singapore, to explore facilitators and barriers faced by them in antimicrobial stewardship. Applied thematic analysis was conducted and codes were categorised using the social-ecological model (SEM). At the intrapersonal level, pharmacists identified themselves as reviewers for drug safety before dispensing, confining to a restricted advisory role due to lack of clinical knowledge, experience, and empowerment to contribute actively to physicians' prescribing decisions. At the interpersonal level, pharmacists expressed difficulties conveying their opinions and recommendations on antibiotic therapy to physicians despite frequent communications, but they assumed critical roles as educators for patients and their caregivers on proper antibiotic use. At the organisational level, in-house antibiotic guidelines supported pharmacists' antibiotic interventions and recommendations. At the community level, pharmacists were motivated to improve low public awareness and knowledge on antibiotic use and antimicrobial resistance. These findings provide important insights into the gaps to be addressed in order to harness the untapped potential of hospital pharmacists and fully engage them in antimicrobial stewardship.

Creation of a Pharmacy Student Longitudinal Rotation to Expand the Scope of an Antimicrobial Stewardship Program

Allergy assessments and penicillin skin testing have emerged as a vital intervention for Antimicrobial Stewardship Programs (ASPs). Investment and involvement in such programs by ASPs, however, are often limited due to resources, time, and personnel constraints. Harnessing an underutilized resource, 4th-year advanced pharmacy practice experience (APPE) students, allows for expanded ASP involvement and scope of practice. We aim to outline and provide insight on how 4th-year APPE students serve as an asset to an ASP. Through our novel longitudinal rotation experience, APPE students complete penicillin allergy assessments, patient education, and work alongside a clinical pharmacist to refer patients for penicillin skin testing if appropriate. Students also achieve many of the education standards required by the Accreditation Counsel for Pharmacy Education (ACPE) for graduation within the Doctor of Pharmacy degree while developing a strong foundation in antimicrobial stewardship and gaining invaluable knowledge for their future. The addition of APPE pharmacy students to our ASP has also enabled our program to achieve its goals and expand involvement and reach within our facility.

Effectiveness and Feasibility of Pharmacist-Driven Penicillin Allergy De-Labeling Pilot Program without Skin Testing or Oral Challenges

Documented penicillin allergies have been associated with an increased risk of adverse outcomes. The goal of this project was to assess the effectiveness and feasibility of a pharmacist-led penicillin allergy “de-labeling” process that does not involve labor-intensive skin testing or direct oral challenges. Adult patients with penicillin allergies were identified and interviewed by an infectious diseases pharmacy resident during a 3-month pilot period. Using an evidence-based standardized checklist, the pharmacist determined if an allergy qualified for de-labeling. In total, 66 patients were interviewed during the pilot period. The average time spent was 5.2 min per patient interviewed. Twelve patients (18%) met the criteria for de-labeling and consented to the removal of the allergy. Four patients (6%) met the criteria but declined removal of the allergy. In brief, 58.3% of patients (7/12) who were de-labeled and 50% of patients (2/4) who declined de-labeling but had their allergy updated to reflect intolerance were subsequently prescribed beta-lactam antibiotics and all (9/9, 100%) were able to tolerate these agents. A pharmacist-led penicillin allergy de-labeling process utilizing a standardized checklist is an effective and feasible method for removing penicillin allergies in patients without a true allergy.

Potential Impact of the Involvement of Clinical Pharmacists in Antimicrobial Stewardship Programs on the Incidence of Antimicrobial-Related Adverse Events in Hospitalized Patients: A Multicenter Retrospective Study

Although specialized pharmacists have been suggested to be essential members of antimicrobial stewardship programs (ASPs), not all hospitals in Korea operate ASPs with pharmacists involved. We aimed to evaluate the association of involvement of clinical pharmacists as team members of multidisciplinary ASPs with the incidence of antimicrobial-related adverse drug events (ADEs). Five tertiary teaching hospitals participated in this retrospective cohort study. At each participating hospital, we randomly selected 1000 participants among patients who had received systemic antimicrobial agents for more than one day during the first quarter of 2017. We investigated five categories of antimicrobial-related ADEs: allergic reactions, hematologic toxicity, nephrotoxicity, hepatotoxicity, and antimicrobial-related diarrhea. Multivariate logistic regression analysis was used to evaluate the potential impact of pharmacist involvement in ASPs on the incidence of ADEs. A total of 1195 antimicrobial-related ADEs occurred in 618 (12.4%) of the 4995 patients included in the analysis. The overall rate of ADE occurrence was 17.4 per 1000 patient days. Hospitals operating ASPs with pharmacists showed significantly lower AE incidence proportions than other hospitals (8.9% vs. 14.7%; p < 0.001). Multidisciplinary ASPs that included clinical pharmacists reduced the risk of antimicrobial-related ADEs by 38% (adjusted odds ratio 0.62; 95% confidence interval 0.50-0.77). Our results suggest that the active involvement of clinical pharmacists in multidisciplinary ASPs may contribute to reduce the incidence of antimicrobial-related ADEs in hospitalized patients.

Beta-lactam allergy labeling in intensive care units: An observational, retrospective study

ABSTRACT

This retrospective study aimed to describe the association between the "β-lactam allergy" labeling (BLAL) and the outcomes of a cohort of intensive care unit (ICU) patients.Retrospective cohort study.Seven ICU of the Aix Marseille University Hospitals from Marseille in France.We collected the uses of the label "β-lactam allergy" in the electronic medical files of patients aged 18 years or more who required more than 48 hours in the ICU with mechanical ventilation and/or vasopressors admitted to 7 ICUs of a single institution.We retrospectively compared the patients with this labeling (BLAL group) with those without this labeling (control group).The primary outcome was the duration of ICU stay. Among the 7146 patients included in the analysis, 440 and 6706 patients were classified in the BLAL group and the control group, respectively. The prevalence of BLAL was 6.2%. In univariate and multivariate analyses, BLAL was weakly or not associated with the duration of ICU and hospital stays (respectively, 6 [3-14] vs 6 [3-14] days, standardized beta -0.09, P = .046; and 18 [10-29] vs 15 [8-28] days, standardized beta -0.09, P = .344). In multivariate analysis, the ICU and 28-day mortality rates were both lower in the BLAL group than in the control group (aOR 0.79 95% CI [0.64-0.98] P = .032 and 0.79 [0.63-0.99] P = .042). Antibiotic use differed between the 2 groups, but the outcomes were similar in the subgroups of septic patients in the BLAL group and the control group.In our cohort, the labeling of a β-lactam allergy was not associated with prolonged ICU and hospital stays. An association was found between the labeling of a β-lactam allergy and lower ICU and 28-day mortality rates.Trial registration: Retrospectively registered.

A comprehensive assessment of carbapenem use across 90 Veterans Health Administration hospitals with defined stewardship strategies for carbapenems

OBJECTIVES

Carbapenems are an important target for antimicrobial stewardship (AS) efforts. In this study, we sought to compare different hospital-based strategies for improving carbapenem use.

METHODS

We analysed a cohort of all patients hospitalized at Veterans Health Administration (VHA) acute care hospitals during 2016 and a mandatory survey that characterized each hospital's carbapenem-specific AS strategy into one of three types: no strategy (NS), prospective audit and feedback (PAF) or restrictive policies (RP). Carbapenem use was compared using risk-adjusted generalized estimating equations that accounted for clustering within hospitals. Two infectious disease (ID) physicians independently performed manual chart reviews in 425 randomly selected cases. Auditors assessed carbapenem appropriateness with an assessment score on Day 4 of therapy.

RESULTS

There were 429 062 admissions in 90 sites (24 NS, 8 PAF, 58 RP). Carbapenem use was lower at PAF than NS sites [rate ratio (RR) 0.6 (95% CI 0.4-0.9); P = 0.01] but similar between RP and NS sites. Carbapenem prescribing was considered appropriate/acceptable in 215 (50.6%) of the reviewed cases. Assessment scores were lower (i.e. better) at RP than NS sites (mean 2.3 versus 2.7; P < 0.01) but did not differ significantly between NS and PAF sites. ID consultations were more common at PAF/RP than NS sites (51% versus 29%; P < 0.01). ID consultations were associated with lower (i.e. better) assessment scores (mean 2.3 versus 2.6; P < 0.01).

CONCLUSIONS

In this VHA cohort, PAF strategies were associated with lower carbapenem use and ID consultation and RP strategies were associated with more appropriate carbapenem prescribing. AS and ID consultations may work complementarily and hospitals could leverage both to optimize carbapenem use.

Frequency of severe reactions following penicillin drug provocation tests: A Bayesian meta-analysis

BACKGROUND

Patients with a penicillin allergy label tend to have worse clinical outcomes and increased healthcare use. Drug provocation tests (DPT) are the gold-standard in the diagnostic workup of penicillin allergy, but safety concerns may hinder their performance. We aimed to assess the frequency of severe reactions following a DPT in patients with reported allergy to penicillins or other β-lactams.

METHODS

We performed a systematic review, searching MEDLINE, Scopus, and Web of Science. We included primary studies assessing participants with a penicillin allergy label who underwent a DPT. We performed a Bayesian meta-analysis to estimate the pooled frequency of severe reactions to penicillin DPTs. Sources of heterogeneity were explored by subgroup and metaregression analyses.

RESULTS

We included 112 primary studies which included a total of 26,595 participants. The pooled frequency of severe reactions was estimated at 0.06% (95% credible interval [95% CrI] = 0.01%-0.13%; I2  = 57.9%). Most severe reactions (80/93; 86.0%) consisted of anaphylaxis. Compared to studies where the index reaction was immediate, we observed a lower frequency of severe reactions for studies assessing non-immediate index reactions (OR = 0.05; 95% CrI = 0-0.31). Patients reporting anaphylaxis as their index reaction were found to be at increased risk of developing severe reactions (OR = 13.5; 95% CrI = 7.7-21.5; I2  = 0.3%). Performance of direct DPTs in low-risk patients or testing with the suspected culprit drug were not associated with clinically relevant increased risk of severe reactions.

CONCLUSIONS

In patients with a penicillin allergy label, severe reactions resulting from DPTs are rare. Therefore, except for patients with potentially life-threatening index reactions or patients with positive skin tests-who were mostly not assessed in this analysis -, the safety of DPTs supports their performance in the diagnostic assessment of penicillin allergy.

Safety and efficacy of de-labelling penicillin allergy in adults using direct oral challenge: a systematic review

Background

Approximately 10% of people have an unverified penicillin allergy, with multiple personal and public health consequences.

Objectives

To assess the efficacy and safety of direct oral challenge, without prior skin testing, in this population.

Methods

MEDLINE, EMBASE, CINAHL, the Cochrane Library and Google Scholar were searched from inception to 28 June 2020 (updated November 2020) to find published and unpublished studies that reported direct oral challenge for the purpose of removal of penicillin allergy labels. Population weighted mean was used to calculate the proportion of patients who developed an immediate or delayed reaction to direct oral challenge across the studies.

Results

Thirteen studies were included in the review, with a sample size of 1202 (range 7–328). Studies included inpatient and outpatient cohorts assessed as low risk for true allergy. In pooled analysis of all 13 studies there were 41/1202 (3.41%) mild immediate or delayed reactions to direct oral challenge. The population-weighted mean incidence of immediate or delayed reaction to an oral challenge across studies was also 3.41% (95% CI: 2.38%–4.43%). There were no reports of serious adverse reactions, 96.5% of patients could be de-labelled and many were subsequently successfully treated with penicillin.

Conclusions

Direct oral challenge is safe and effective for de-labelling patients assessed as low risk for true allergy. Non-specialist clinicians competent in using an assessment algorithm can offer evaluation of penicillin allergy labels using direct oral challenge in appropriate patients. These measures will facilitate optimal infection treatment for patients, support antimicrobial stewardship, and minimize antimicrobial resistance.

Are We Making the Most of Community Pharmacies? Implementation of Antimicrobial Stewardship Measures in Community Pharmacies: A Narrative Review

Community pharmacists recognize the need to implement antimicrobial stewardship activities in community pharmacies. They are in a unique position to provide triage for common primary care indications and to lower the burden of patients at general practitioners’ offices. However, research shows that, in some areas, dispensing of antimicrobials without valid prescription is still highly prevalent. Regardless of training, every community pharmacist can give his contribution to antimicrobial stewardship. One of the basic elements should be antimicrobial dispensing according to regulations, either prescription only, or according to guidelines where pharmacists have prescribing authority. Patient consultation supported with educational materials, such as leaflets, may reduce patients’ expectations to receive antibiotics for self-limiting infections and reduce pressure on general practitioners to prescribe antibiotics on patients’ demand. Treatment optimization may be achieved in collaboration with the prescribing general practitioners or by providing feedback. At last, pharmacists provided with additional training may be encouraged to provide consultation services to long-term care facilities, to introduce point-of-care testing for infectious diseases in their pharmacies or prescribe antimicrobials for uncomplicated infections. These services are welcomed by patients and communities. Expanding pharmacy services and pharmacists’ prescribing autonomy have shown a positive impact by reducing antibiotics consumption, thus ensuring better compliance with treatment guidelines.

Reported β-Lactam and Other Antibiotic Allergies in Solid Organ and Hematopoietic Cell Transplant Recipients

BACKGROUND

Patients with reported β-lactam antibiotic allergies (BLAs) are more likely to receive broad-spectrum antibiotics and experience adverse outcomes. Data describing antibiotic allergies among solid organ transplant (SOT) and hematopoietic cell transplant (HCT) recipients are limited.

METHODS

We reviewed records of adult SOT or allogeneic HCT recipients from 1 January 2013 to 31 December 2017 to characterize reported antibiotic allergies at time of transplantation. Inpatient antibiotic use was examined for 100 days posttransplant. Incidence rate ratios (IRRs) comparing antibiotic use in BLA and non-BLA groups were calculated using multivariable negative binomial models for 2 metrics: days of therapy (DOT) per 1000 inpatient days and percentage of antibiotic exposure-days.

RESULTS

Among 2153 SOT (65%) and HCT (35%) recipients, 634 (29%) reported any antibiotic allergy and 347 (16%) reported BLAs. Inpatient antibiotics were administered to 2020 (94%) patients during the first 100 days posttransplantation; average antibiotic exposure was 41% of inpatient-days (interquartile range, 16.7%-62.5%). BLA patients had significantly higher DOT for vancomycin (IRR, 1.4 [95% confidence interval {CI}, 1.2-1.7]; P < .001), clindamycin (IRR, 7.6 [95% CI, 2.2-32.4]; P = .001), and aztreonam in HCT (IRR, 9.7 [95% CI, 3.3-35.0]; P < .001), and fluoroquinolones in SOT (IRR, 2.9 [95% CI, 2.1-4.0]; P < .001); these findings were consistent when using percentage of antibiotic exposure-days.

CONCLUSIONS

Transplant recipients are frequently exposed to antibiotics and have a high prevalence of reported antibiotic allergies. Reported BLA was associated with greater use of β-lactam antibiotic alternatives. Pretransplant antibiotic allergy evaluation may optimize antibiotic use in this population.

Antibiotic allergy labels and optimal antimicrobial stewardship

BACKGROUND

Although common, antimicrobial allergy labels (AAL) rarely reflect immunologically-mediated hypersensitivity and can lead to poorer outcomes from alternative antimicrobial agents. Antimicrobial stewardship programs are ideally placed to assess AAL early as a means of improving antimicrobial use.

OBJECTIVES

To quantify the prevalence of AAL in patients referred for antimicrobial stewardship review and assess their impact on antibiotic prescribing, patient mortality, hospital length of stay, readmission, and rates of multidrug-resistant infections.

METHODS

We conducted a retrospective analysis of adult patients referred for inpatient antimicrobial prospective audit and feedback rounds (PAFR) via an electronic referral system (eReferrals) over a 12-month period in 2015. Outcome data was collected for a period of 36 months following the initial review.

RESULTS

Of the 639 patient records reviewed, 630 met inclusion criteria; 103 (16%) had an AAL, of which 82 (13%) had reported allergies to β-lactam antibiotics. Those with AAL were significantly less likely to be receiving guideline-recommended antimicrobial therapy (50% versus 64%, p=0.0311), however there were no significant difference in mortality, hospital length of stay, readmission or increased incidence of multidrug-resistant infections.

CONCLUSIONS

Our cohort demonstrated that AAL was associated with reduced adherence to antibiotic guidelines. The lack of association with adverse outcomes may reflect limitations within the study including retrospective cohort study numbers and observational nature, further skewed by high rates of poor documentation. A clear opportunity exists for antimicrobial stewardship programs to incorporate allergy assessment, delabelling, challenge and referral into these rounds. This article is protected by copyright. All rights reserved.

The democratization of de-labeling: a review of direct oral challenge in adults with low-risk penicillin allergy

INTRODUCTION

Penicillin antibiotic allergy labels (AALs) are common and lead to significant negative health and health system outcomes. Direct oral challenge offers a rapid and cost-effective way of removing inaccurate AALs and improving outcomes.

AREAS COVERED

A narrative review (Medline, May 2020) of direct oral challenge in low-risk penicillin allergy in adults is described, and the evidence for the safety and efficacy of this approach in inpatients, outpatients, and special patient groups is presented.

EXPERT OPINION

Whilst the current literature demonstrates the safety and efficacy of direct oral challenge in de-labeling low-risk penicillin allergy in adults, novel approaches are needed to improve access to antibiotic allergy assessment and address the growing global need.