Implementation of a pharmacist-led outpatient penicillin allergy testing clinic

BACKGROUND

Penicillin allergies affect approximately 10% of the population, leading to increased health care costs, treatment failures, and multidrug resistant organisms.

OBJECTIVE

To determine the feasibility of implementing a pharmacist-led outpatient penicillin allergy testing program.

METHODS

This single-site, retrospective cohort study was conducted from July 2022 through December 2023. The study site consisted of an outpatient clinic within a nonacademic community hospital. The primary outcome was the percentage of patients who had their penicillin allergy delabeled. Secondary outcomes included percentage of patients who received appropriate antibiotics following allergy delabeling, incidence and type of immunoglobulin E mediated penicillin reactions, number of patients who were relabeled with a penicillin allergy, number of orthopedic patients with a postoperative surgical site infection, average reimbursement per patient, and average appointment time.

RESULTS

A total of 457 outpatients received penicillin allergy testing during the study period. Physician specialties who referred patients were orthopedics, obstetrician-gynecologists, infectious disease, urology, urogynecology, cardiothoracic surgeons, and primary care providers. For the primary outcome, 439 patients (96%) were successfully delabeled. All delabeled patients received appropriate antibiotics following testing. There were 17 patients who developed minor itching with or without a localized rash following the amoxicillin challenge, and one patient had a delayed reaction of rash 12 hours after the amoxicillin that resolved with an antihistamine. One patient had their penicillin allergy relabeled. Of the 192 orthopedic patients, 0 patients had a postoperative surgical site infection. The average reimbursement was $423 per patient with the average appointment lasting 96 minutes.

CONCLUSION

Pharmacists, in collaboration with multiple physician specialties, successfully implemented an outpatient penicillin allergy testing service to safely delabel patients and support antimicrobial stewardship.

Nonallergist Delabeling-Should Penicillin Allergy Delabeling Only Be Performed by Allergists?

Penicillin allergy labels (PAL) are common but rarely correspond with a patient's likelihood to tolerate penicillin. This results in unnecessary penicillin avoidance in many patients, driving numerous negative health outcomes. Evaluation strategies for a PAL are driven by risk stratification and include a spectrum of modalities such as delabeling without any testing, direct oral challenge, and skin testing followed by challenge testing. Historically, PAL delabeling has primarily been the domain of the allergist, but this has resulted in significant limitations in access to testing for many patients globally and in the United States. Novel strategies to increase access to penicillin allergy evaluations are urgently needed, and nonallergist delabeling has been proposed as one strategy to help address this. Using a pro/con format, we review the evidence for nonallergist PAL delabeling in children and adults, focusing on direct challenge testing and highlighting considerations to guide nonallergist implementation of penicillin allergy evaluations.

Antibiotic use and financial impact of a comprehensive beta-lactam allergy management program

Objective

A multidisciplinary beta-lactam allergy management program was implemented at our community medical center to facilitate allergy documentation, conduct penicillin skin testing (PST), and decrease non-beta-lactam (NBL) use. This study measures PST-associated antibiotic use and financial outcomes.

Design

Cohort study.

Setting

Non-teaching, urban, community medical center within a multi-hospital health system.

Patients

Adult inpatients who underwent PST and received antibiotic therapy during a 5-year period at our facility.

Methods

Demographics, allergies, laboratory results, PST outcome, and antimicrobial regimens were assessed. Actual NBL days of therapy (DOT) were collected from the electronic medical record. NBL DOT that patients would have received without PST were modeled by forecasting the original regimen to end of inpatient treatment. Difference between actual and forecasted DOT was deemed DOT avoided (DOT-A) for each consecutively enrolled patient. The financial analysis evaluated cumulative NBL cost avoided. PST outcomes and average time from antibiotic initiation to PST were assessed.

Results

The study included 600 patients who underwent PST an average of 3.7 days into treatment. The most common indication was acute bacterial skin and skin structure infections (23.9%). PST results were negative in 98% of patients. NBL DOT-A was 944.8/1000DT (8.8 DOT-A per intervention) accounting for an estimated cost savings of $206,500 ($344.10 per intervention), driven primarily by aztreonam avoidance.

Conclusions

This study highlights significant avoidance of NBL DOT in one of the largest identified cohort of inpatients undergoing PST. Associated cost avoidance contributes to the sustainability and longevity of the allergy management program.

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.

Beta-lactam allergy in patients: an antibiotic stewardship challenge

BACKGROUND

Patients are commonly reported as being allergic to beta-lactam (BL) antibiotics. However, many patients with this reported allergy are able to receive BL treatments because they do not have true allergies. In many cases these are simply intolerances due to side effects reported as an allergy. Delabelling these patients leads to better clinical outcomes, optimal antibiotic usage, decreased bacterial resistance and reduced healthcare costs. Therefore, the aims of this study were to identify incorrectly labelled BL allergies in hospitalised patients and to assess antibiotic use in delabelled patients in order to establish a quality indicator to optimise antimicrobial treatments.

METHODS

A prospective study was conducted in which hospitalised patients treated with antimicrobial drugs and labelled as 'BL-allergic' were identified by clinical pharmacists. An allergist assessed whether patients were suitable candidates for a skin test or oral challenge. The Allergy Service removed 'BL-allergic' labels if negative results were obtained. Delabelled patients were followed up by clinical pharmacists to study the use of BL antibiotics as a result of the delabelling programme.

RESULTS

A total of 176 suspected allergic patients were identified and 91 (51.7%) were tested either by a skin test or oral challenge based on the patient indicators. Seven (16.4%) patients tested were allergic to BL antibiotics, 76 (83.5%) were totally delabelled and eight (0.1%) were partially delabelled. Thirty-two (38.1%) delabelled patients required antibiotic treatment in another inpatient or outpatient setting, of whom 27 (84.3%) patients with a new infectious episode received BL treatments while five (15.7%) continued to receive antimicrobial treatments without BL.

CONCLUSION

After the implementation of a protocol to detect incorrect BL allergy labels, 83.5% of the patients in this cohort were completely delabelled. This shows that there is a clear opportunity to optimise the use of antibiotics by delabelling 'BL-allergic' patients.

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.

Penicillin allergy delabeling: Opportunities for implementation and dissemination

Although existing as a safety measure to prevent iatrogenic harm, unconfirmed penicillin allergy labels have a negative impact on personal and public health. One downstream effect of unconfirmed penicillin allergy is the continued emergence and transmission of resistant bacteria and their associated health care costs. Recognizing the consequences of inaccurate penicillin allergy labels, professional and public health organizations have started promoting the adoption of proactive penicillin allergy evaluations, with the ultimate goal of removing the penicillin allergy label when the allergy is disproved, also known as penicillin allergy "delabeling." A penicillin allergy evaluation includes a comprehensive allergy history often followed by drug challenge, sometimes with preceding skin testing. Currently, penicillin allergy delabeling is largely carried out by allergy specialists in outpatient settings. Penicillin allergy delabeling is performed on inpatients, albeit rarely, often at the time of need, as a point-of-care procedure. Access to penicillin allergy evaluation services is limited. Recent studies demonstrate the feasibility of expanding penicillin allergy evaluations and delabeling to internists, pediatricians, emergency medicine physicians, infectious diseases specialists, and clinical pharmacists. However, reducing the impact of mislabeled penicillin allergy will require comprehensive efforts and new investments. In this review, we summarize the current practices of penicillin allergy delabeling and discuss expansion opportunities for penicillin allergy delabeling as quality improvement.

Treatment of Helicobacter pylori Infection in Patients with Penicillin Allergy

Helicobacter pylori is among the prevalent causes of infections worldwide, and its resistance rate to antibiotics has been rising over time. Amoxicillin is the cornerstone for the treatment regimen. However, the prevalence of penicillin allergy ranges from 4% to 15%. In patients with true allergy, Vonoprazan-Clarithromycin-Metronidazole and bismuth quadruple therapy have demonstrated excellent eradication and high adherence rates. Vonoprazan-based therapy is administered less frequently and may be better tolerated than bismuth quadruple therapy. Therefore, vonoprazan-based therapy may be considered as a first-line therapy if accessible. Bismuth quadruple therapy can be used as the initial therapy when vonoprazan is unavailable. Levofloxacin or sitafloxacin-based regimens achieve a moderately high eradication rate. However, these are associated with potentially serious adverse effects and should only be used when other effective and safer regimens are unavailable. Cephalosporins such as cefuroxime have been used as an alternative to amoxicillin. Microbial susceptibility studies can guide the selection of appropriate antibiotics. PPI-Clarithromycin-Metronidazole fails to achieve a high eradication rate and should be used as a second-line therapy. PPI-Clarithromycin-Rifabutin should not be used because of low eradication rate and frequent adverse reactions. The choice of the most effective antibiotic regimen can enhance clinical outcomes in patients with H. pylori infection and penicillin allergy.

Variation Among Infectious Diseases Pharmacists for the Treatment of Staphylococcus aureus Bacteremia

Introduction: Staphylococcus aureus bacteremia (SAB) remains complex, in that optimal treatment for patients, including complicated or persistent infection, remains unclear. Two recent surveys have demonstrated practice variations in SAB among infectious diseases (ID) physicians. Objectives: The purpose of this survey was to examine practice variations in SAB among ID pharmacists. Methods: A thirty-five-question survey was electronically distributed to the American College of Clinical Pharmacy (ACCP) Infectious Diseases Practice and Research Network (IDPRN) in Fall 2019 to determine differences in SAB management. Data were analyzed utilizing Pearson's Chi-Square or Fisher's Exact Test. Results: A total of 106 ID pharmacists responded. Only 28% of pharmacists practiced at hospitals with mandatory ID consultation for SAB. A majority (75%) had rapid diagnostic technology (RDT) for identifying SABSI, but 32% of those facilities with RDT did not notify pharmacy with results. Anti-staphylococcal penicillins were preferred for MSSA blood stream infections (BSI) in patients with central nervous system infection and endocarditis, whereas cefazolin was favored for other MSSA BSI. For persistent MRSA BSI, 34% selected daptomycin alone while 38% elected to combine daptomycin and ceftaroline. Pharmacists at hospitals less than 500 beds were more likely to use daptomycin, while those at larger hospitals were more likely to use daptomycin and ceftaroline for persistent MRSA BSI (P < .05). Conclusions: A survey of ID pharmacists showed variation in the management of SABs, as well as the definition and treatment of persistent SAB. Mandatory ID consultation and RDT use to improve SAB management have not been optimized.

Hong Kong Drug Allergy Delabelling Initiative (HK-DADI) consensus statements for penicillin allergy testing by nonallergists

Introduction

Penicillin allergy testing has been traditionally performed by allergists, but there remains a huge deficit of specialists. A multidisciplinary effort with nonallergists would be invaluable to overcome the magnitude of penicillin allergy labels via the Hong Kong Drug Allergy Delabelling Initiative (HK-DADI). These consensus statements (CSs) offer recommendations and guidance to enable nonallergists to screen for low-risk (LR) patients and perform penicillin allergy testing.

Methods

CSs were formulated by the HK-DADI Group using the Delphi method. An agreement was defined as greater than or equal to 80% consensus.

Results

A total of 26 CSs reached consensus after multiple rounds of Delphi. CSs were categorized into risk assessment, skin testing, drug provocation testing (DPT), and post-testing management. For risk assessment, the essentials of allergy history and exclusion criteria were detailed. Patients with only LR features can proceed with testing by nonallergists. Skin tests should be performed prior to DPT. Details regarding the timing, preparation, and interpretation of skin tests were elaborated. DPT remains the gold standard to diagnose genuine allergy or tolerance and should be performed when there is a low pretest probability following negative skin testing. Details of DPT preparations, dosing protocols, and interpretation were elaborated. For post-testing management, inaccurate allergy labels should be delabeled following negative DPT with proper patient counseling.

Conclusion

CSs support penicillin allergy testing by nonallergists in Hong Kong. LR cases can be managed by nonallergists at Spoke Clinics, with training and support of an allergist-led Hub.

Review of Pharmacist Driven Penicillin Allergy Assessments and Skin Testing: A Multi-Center Case-Series

Objective: To describe the impact of pharmacy driven penicillin allergy assessments on de-labeling penicillin allergies and antibiotic streamlining opportunities for hospitalized patients. Design: Multi-center, retrospective case-series study. Setting: A health system of 4 non-teaching hospitals. Participants: Patients aged 18 years and older with a physician order for a pharmacist penicillin allergy assessment. Exclusion criteria consisted of patients with anaphylaxis or a type II penicillin allergy, anaphylaxis of any cause within 4 weeks, refusal of penicillin allergy skin test (PAST), antihistamine use within 24 hours, penicillin intolerance, immunosuppression or immunosuppressive medications, or skin conditions that could interfere with PAST. Interventions: The primary endpoint evaluated the number of de-labeled penicillin allergies after pharmacists provided penicillin allergy assessments. Secondary endpoints evaluated the percent of patients with antibiotics deescalated to beta-lactam antibiotics and classification of notable interventions made by pharmacists. Measurements and Main Results: There were 35 patients who met inclusion criteria. Twenty-four patients underwent both penicillin allergy skin testing and oral (PO) amoxicillin challenge. Five patients had allergies de-labeled only after a pharmacist interview. Four patients received only the PO amoxicillin challenge and 2 patients received only PAST. Penicillin allergies were de-labeled from the electronic health record (EHR) in 31 (89%) patients despite all testing negative for a penicillin allergy from PAST or a PO amoxicillin challenge. Four patients had the allergy re-added to the chart on subsequent admissions. No patients experienced a reaction from PAST, PO amoxicillin challenge, or subsequent beta-lactam antibiotics. Twenty-eight (80%) patients had their antibiotic therapy changed as a result of the allergy assessment. Seventeen patients were de-escalated onto beta-lactam antibiotics and aztreonam was stopped in 6 patients. Conclusion: Results from this study suggests that pharmacists expanding their scope of practice with PAST is a safe and effective allergy de-labeling tool. Pharmacist-driven penicillin allergy assessments could provide antibiotic cost savings and avoid aztreonam use. The study supports the need to emphasize education for patients and caretakers regarding allergy testing results to avoid relabeling in future hospital visits.

Instruction and Simulation to Improve Pharmacy Students' Knowledge and Confidence Regarding Assessment of Penicillin Allergies

Objective. To evaluate pharmacy students' knowledge of and confidence regarding penicillin allergy assessment and skin testing (PAAST) before and after a focused didactic instruction and simulation (FDIS).Methods. A multicenter, quasi-experimental, cross-sectional survey study was performed among pharmacy students before and after FDIS on PAAST at two schools of pharmacy. The FDIS on PAAST consisted of an infectious disease faculty-led seminar, student-led penicillin allergy counseling interviews, penicillin skin testing simulation, and case studies to assess penicillin allergy scenarios and management. An anonymous, voluntary, electronic survey was distributed to students (n=159) before and after the FDIS. The pre- and post-intervention survey contained 10 PAAST knowledge-based questions and multi-step, five-point Likert scale statements related to students' confidence in PAAST. The post-intervention survey also evaluated students' perceptions of the FDIS on PAAST. Descriptive statistics were performed, and the Student t test was used to compare pre- and post-intervention responses.Results. One hundred forty-three surveys were completed, resulting in a survey response rate of 90%. Students' PAAST knowledge scores (mean±SD) increased overall following the FDIS on PAAST (6.67±1.51 vs 7.81±1.39). Knowledge scores increased considerably for questions related to penicillin allergy consequences, cross-reactivity, and correct steps of PAAST. Pharmacy students' PAAST confidence scores (mean±SD) also improved following the interactive instruction and simulation (2.30±0.7 vs 3.22±0.67) with considerable confidence increases in penicillin skin testing. Pharmacy students' perceptions of the FDIS on PAAST were also positive overall.Conclusion. Pharmacy students' knowledge and confidence of PAAST improved following FDIS. This may be an effective strategy to implement PAAST education during pharmacy school.

Antibiotic Use in Patients With β-Lactam Allergies and Pneumonia: Impact of an Antibiotic Side Chain-Based Cross-Reactivity Chart Combined With Enhanced Allergy Assessment

BACKGROUND

β-lactam antibiotics with dissimilar R-group side chains are associated with low cross-reactivity. Despite this, patients with β-lactam allergies are often treated with non-β-lactam alternative antibiotics. An institutional β-lactam side chain-based cross-reactivity chart was developed and implemented to guide in antibiotic selection for patients with β-lactam allergies.

METHODS

This single-center, retrospective cohort study analyzed the impact of the implementation of the cross-reactivity chart for patients with pneumonia. Study time periods were defined as January 2013 to October 2014 prior to implementation of the chart (historical cohort) and January 2017 to October 2018 (intervention cohort) following implementation. The primary outcome was the incidence of β-lactam utilization between time periods. Propensity-weighted scoring and interrupted time-series analyses compared outcomes.

RESULTS

A total of 341 and 623 patient encounters were included in the historical and intervention cohorts, respectively. There was a significantly greater use of β-lactams in the intervention cohort (70.4% vs 89.3%; P < .001) and decreased use of alternative therapy (58.1% vs 36%; P < .001). There was no difference in overall allergic reactions between cohorts (2.4% vs 1.6%; P = .738) or in reactions caused by β-lactams (1.3% vs 0.9%; P = .703). Inpatient mortality increased (0% vs 6.4%; P < .001); however, no deaths were due to allergic reactions. Healthcare facility-onset Clostridioides difficile infections decreased between cohorts (1.2% vs 0.2%; P = .032).

CONCLUSIONS

Implementation of a β-lactam side chain-based cross-reactivity chart and enhanced allergy assessment was associated with increased use of β-lactams in patients with pneumonia without increasing allergic reactions.

New perspectives on propofol allergy

PURPOSE

Propofol is an intravenous sedative used in many patient populations and care settings. Although generally considered safe and effective, the drug has historically been avoided in patients with reported allergies to egg, soy, and/or peanut on the basis of the manufacturer's prescribing information. Concerns exist for potential adverse events, increased medication costs, reduced efficacy, and risk of medication errors when using alternative agents. Here we present a critical examination of the literature concerning cross-reactivity of food allergies with propofol to provide evidence-based recommendations for the evaluation and management of potential allergic reactions.

SUMMARY

Literature regarding the history of propofol allergy warnings and clinical trial data were assessed to provide an alternative perspective on avoidance of propofol in patients with food allergies. Suspected trigger molecules are discussed with evaluation of the antigenic potential of excipient ingredients used in the manufacture of multiple propofol formulations. Evidence-based recommendations are provided for pharmacist-led screening of adult patients with reported food allergies to support selection of propofol or alternative therapy.

CONCLUSION

There is a lack of definitive evidence that propofol must be routinely avoided in patients with reported allergies to egg, soy, and/or peanut products. Data from clinical trials suggest that propofol is safe for patients with nonanaphylactic food allergies. Patients who do experience allergic reactions following administration of propofol should undergo further testing to definitively identify the specific trigger and prevent future unnecessary avoidance of preferred medication regimens. Pharmacists can play an important role in interviewing patients with reported food allergies to better determine the risk vs benefit of propofol avoidance.

Overview of Beta-Lactam Allergy and the Role of the Pharmacist in Management

Unverified beta-lactam allergies are a substantial public health problem, as the majority of patients labeled as beta-lactam allergic do not have clinically significant allergies that may hinder the use beta-lactam therapy when indicated. Outdated or inaccurate beta-lactam or penicillin allergies can result in serious consequences, including suboptimal antibiotic therapy, increased risk of adverse effects, and use of broader spectrum antibiotics than indicated, which may contribute to antimicrobial resistance. The purpose of this review is to provide an overview of beta-lactam allergy and highlight the role of pharmacists in managing beta-lactam allergies. Studies have shown that pharmacists can play a vital role in allergy assessment, penicillin skin testing, beta-lactam desensitization, evaluation of beta-lactam cross-reactivity and recommending appropriate antibiotic therapy in patients with beta-lactam allergies.

Description of a pharmacist-managed/administered penicillin allergy skin testing service at a community hospital

PURPOSE

To describe how a pharmacist-managed and pharmacist-administered penicillin allergy skin testing (PAST) service was incorporated into an antimicrobial stewardship program at a community hospital.

METHODS

A pharmacist-managed/administered PAST service was initiated in October 2015. Patients 18 years of age or older were considered for PAST if they had a reported history of a type I or unknown type of allergic reaction to penicillin that occurred more than 5 years previously. Patients with a vague allergy history were considered for PAST if the provider was uncomfortable prescribing a preferred β-lactam out of concern for penicillin allergy. Patients were excluded if they were pregnant, had a history of a non-type I allergic reaction, or recently received antihistamines. The primary outcome was the percentage of patients who underwent PAST and were subsequently transitioned to a preferred β-lactam.

RESULTS

PAST was initiated in 90 patients from October 2015 to December 2019. Eighty-five out of 90 patients (94%) completed PAST. Seventy-six out of 90 patients (84.4%) who underwent PAST were transitioned to a preferred β-lactam. The most commonly administered antibiotics prior to PAST were vancomycin, cefepime, and metronidazole. The most commonly used antibiotics after PAST were penicillin, piperacillin/tazobactam, and ampicillin/sulbactam. Among the 90 patients who underwent PAST, alternative antibiotics were avoided for a total of 1,568 days, with a median of 11 days (interquartile range, 6-18 days) avoided per patient.

CONCLUSION

Incorporating a pharmacist-managed/administered PAST service into a community hospital's antimicrobial stewardship program can improve the utilization of preferred antimicrobial therapy and help avoid use of more toxic, costly antimicrobials.

Impact of an Antibiotic Side-Chain-Based Cross-reactivity Chart Combined With Enhanced Allergy Assessment Processes for Surgical Prophylaxis Antimicrobials in Patients With β-Lactam Allergies

BACKGROUND

β-Lactam antibiotics are first-line therapy for perioperative prophylaxis; however, patient-reported allergies often lead to increased prescribing of alternative antibiotics that may increase the incidence of surgical site infections. The R-group side chain of the β-lactam ring is responsible for allergic cross-reactivity and experts recommend the use of β-lactams that are structurally dissimilar.

METHODS

An internally developed, antibiotic side-chain-based cross-reactivity chart was developed and implemented alongside enhanced allergy assessment processes. This single-center, quasi-experimental study analyzed antibiotic prescribing in all adult patients with a documented β-lactam allergy undergoing an inpatient surgical procedure between quartile (Q) 1 (2012)-Q3 (2014) (historical group) and Q3 (2016)-Q3 (2018) (intervention group). Propensity-weighted scoring analyses compared categorical and continuous outcomes. Interrupted time-series analysis further analyzed key outcomes.

RESULTS

A total of 1119 and 1089 patients were included in the historical and intervention cohorts, respectively. There was a significant difference in patients receiving a β-lactam alternative antibiotic between cohorts (84.9% vs 15.1%; P < .001). There was a decrease in 30-day readmissions in the intervention cohort (7.9% vs 6.3%; P = .035); however, there was no difference in the incidence of SSIs in patients readmitted (14.8% vs 13%; P = .765). No significant differences were observed in allergic reactions (0.5% vs 0.3%; P = .323), surgical site infections, in-hospital and 30-day mortality, healthcare facility-onset Clostridiodes difficile infection, acute kidney injury, or hospital costs.

CONCLUSIONS

Implementation of an antibiotic cross-reactivity chart combined with enhanced allergy assessment processes significantly improved the prescribing of β-lactam antibiotics for surgical prophylaxis.

Penicillin Allergy Delabeling: A Multidisciplinary Opportunity

The penicillin allergy label has been consistently linked with deleterious effects that span the health care spectrum, including suboptimal clinical outcomes, the emergence of bacterial resistance, and increased health care expenditures. These risks have recently motivated professional organizations and public health institutes to advocate for the implementation of penicillin allergy delabeling initiatives; however, the burden of delabeling millions of patients is too expansive for any one discipline to bear alone. This review presents the unique perspectives and roles of various stakeholder groups involved in penicillin allergy diagnosis, assessment, and delabeling; we emphasize opportunities, barriers, and promising areas of innovation. We summarize penicillin allergy methods and tools that have proven successful in delabeling efforts. A multidisciplinary approach to delabeling patients with reported penicillin allergy, bolstered by evidence-based clinical practices, is recommended to reduce the risks that associate with the penicillin allergy label.

Penicillin Allergy Testing: An Outpatient Nurse-Driven Program for Patients With Cancer

BACKGROUND

Penicillin allergy testing (PAT) can decrease the use of unnecessary antibiotics by clarifying who is truly allergic.

OBJECTIVES

This article describes the development and implementation of an oncology outpatient nurse-driven PAT program.

METHODS

A nurse-driven program, initiated with allergy screening at the first encounter, was designed to identify patients with oncologic diagnoses eligible for PAT. Once verified eligible, patients undergo a three-step testing process (scratch test, intradermal injection, and IV challenge dose) administered by the infusion nurse.

FINDINGS

From November 2018 to December 2019, 82 outpatients with reported penicillin allergies were screened; 90% were eligible for PAT, and 97% of patients tested were negative for penicillin allergy. A significant reduction in aztreonam use among patients admitted for hematopoietic stem cell transplantation was also noted as compared to before PAT was offered.

Skin Testing for Penicillin Allergy: a Review of the Literature

PURPOSE OF REVIEW

Self-reported penicillin allergies are frequently reported, though more than 95% of those are not truly allergic when challenged. These patients are more likely to receive alternative antibiotic regimens resulting in the use of broad-spectrum antibiotics that may be less effective, more toxic, and/or more expensive than preferred agents. Given the significant burden on patient outcomes and the healthcare system, the ability to reconcile an allergy and broaden future antibiotic options is essential.

RECENT FINDINGS

This is a narrative review describing risk stratification for penicillin skin testing, practical advice for implementation, and future directions. A summary of studies within the last 5 years is provided. The trend over the past several years has been to offer oral drug challenges to low-risk patients and skin testing to high-risk patients with a reported penicillin allergy. This review provides support for risk stratification assessment of reported penicillin allergy to optimize antibiotic use and prevent emergence of antimicrobial resistance.

Safety and efficacy of direct two-step penicillin challenges with an inpatient pharmacist-driven allergy evaluation

Background: Penicillin allergy is commonly reported and has clinical and financial consequences for patients and hospitals. A penicillin evaluation program can safely delabel patients and optimize antibiotic therapy. Pharmacists who perform this task have focused on a detailed interview or penicillin skin testing (PST). Antibiotic graded challenge after PST requires more resources and is more costly than going directly to a two-step challenge. Objective: To determine whether a pharmacist-driven penicillin allergy evaluation and a testing protocol that primarily uses direct oral challenges can safely delabel patients. Methods: Adult patients (ages >18 years) with a penicillin allergy in their electronic medical record (EMR) who were admitted between September 2019 and June 2020 were eligible. Although all patients with penicillin allergy were eligible, priority was given to patients who required antibiotics. Patients were interviewed, and, if indicated, based on an institutional protocol, were tested by using PST and/or two-step oral challenge. If the patient passed the challenge, then the penicillin allergy label was removed in the EMR and the patient counseled. Demographic information, allergy questionnaire results, testing results, and changes in antimicrobial therapy were collected. Results: Fifty patients were evaluated from September 2019 to June 2020. Ninety-six percent of the patients were delabeled, and antibiotic therapy changed for 54%. Twenty patients were delabeled with an interview alone, and 30 patients underwent oral two-step challenge. Only one patient required PST. Conclusion: A pharmacist-driven penicillin allergy evaluation program focused on direct oral graded challenges and bypassing PST can effectively delabel admitted patients. However, more safety data are needed before implementation of similar programs to optimize antibiotic treatment.

Interventions to optimize antimicrobial stewardship

Developing and improving an antimicrobial stewardship program successfully requires evaluation of numerous factors. As technology progresses and our understanding of antimicrobial resistance grows, careful consideration should be taken to ensure that a program meets the needs of the institution and is achievable given the available resources. In this review, we explore fundamental initiatives and strategies for both new and established antimicrobial stewardship programs, including the specific areas to target and key elements required for sustainable implementation.

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.

The economics of drug allergy

PURPOSE OF REVIEW

As drug allergy research aims to inform clinical practice, implementation of best practices may be influenced by financial resources required to incorporate new interventions and the resulting clinical and economic returns on those resource investments. The present review summarizes new insights into the economics of drug allergy over the past year.

RECENT FINDINGS

While considering economic implications of recent drug allergy research, many studies have addressed different contextual factors related to the setting, provider, or outcomes. Advances in technology have enabled specialized allergists to support remote settings through telemedicine consultation. Training opportunities and interdisciplinary approaches to address drug allergy challenges have enabled multiple provider types to play a role in screening, diagnosis, and management. Penicillin allergy testing has been a major focus for many institutions, with several studies focused on de-labeling strategies including confirmatory skin testing and direct oral challenges.

SUMMARY

Studies over the past year provide new opportunities for the field of drug allergy research. The focus of current research to capture direct health costs or savings associated with drug allergy interventions demonstrates opportunity for more cost-effective care delivery and opportunity to explore greater benefits to society.

Inpatient Antibiotic Stewardship Interventions in the Adult Oncology and Hematopoietic Stem Cell Transplant Population: A Review of the Literature

Objective: To review the use of antibiotic stewardship interventions in the adult oncology and hematopoietic cell transplantation (HCT) populations. Data Sources: A literature search of PubMed was performed from inception to October 31, 2019. The general search terms used were oncology, cancer, hematologic malignancy, antimicrobial stewardship, antibiotic stewardship, febrile neutropenia, neutropenic fever, de-escalation, discontinuation, prophylaxis, practice guidelines, clinical pathway, rapid diagnostics, Filmarray, Verigene, MALDI-TOF, antibiotic allergy, and antimicrobial resistance. Study Selection and Data Extraction: Relevant English-language studies describing interventions supported by the Infectious Diseases Society of America guidelines on "Implementing an Antibiotic Stewardship Program" were included. Data Synthesis: Antibiotic stewardship publications in the oncology population have increased in recent years. Studies have described the impact of stewardship interventions, including preauthorization, prospective audit and feedback, implementation of clinical pathways, de-escalation of empirical antibiotics for febrile neutropenia (FN) prior to neutrophil recovery, allergy assessments, and use of rapid diagnostic testing. Many of these interventions have been shown to decrease antibiotic use without increased negative consequences, such as affecting length of stay or mortality. Relevance to Patient Care and Clinical Practice: This review synthesizes available evidence for implementing antibiotic stewardship interventions, particularly de-escalation of antibiotics for FN and implementation of clinical pathways for FN and sepsis, in oncology patients and HCT recipients. Summary tables highlight studies and specific research needs for clinicians. Conclusions: Immunocompromised populations, including oncology patients, have often been excluded from stewardship studies. Antibiotic stewardship is effective in reducing antibiotic consumption and improving outcomes in this patient population, although more quality data are needed.

Penicillin Allergy Assessment and Skin Testing in the Outpatient Setting

Penicillin allergies are among of the most commonly reported allergies, yet only 10% of these patients are truly allergic. This leads to potential inadvertent negative consequences for patients and makes treatment decisions challenging for clinicians. Thus, allergy assessment and penicillin skin testing (PST) are important management strategies to reconcile and clarify labeled penicillin allergies. While PST is more common in the inpatient setting where the results will immediately impact antibiotic management, this process is becoming of increasing importance in the outpatient setting. PST in the outpatient setting allows clinicians to proactively de-label and educate patients accordingly so beta-lactam antibiotics may be appropriately prescribed when necessary for future infections. While allergists have primarily been responsible for PST in the outpatient setting, there is an increasing role for pharmacist involvement in the process. This review highlights the importance of penicillin allergy assessments, considerations for PST in the outpatient setting, education and advocacy for patients and clinicians, and the pharmacist’s role in outpatient PST.

Penicillin Allergy Skin Testing in the Inpatient Setting

The consequences of a documented penicillin allergy in the medical record are especially troublesome in acutely ill, hospitalized patients. A penicillin allergy label may lead to alternative or second line therapies resulting in adverse drug events, negative clinical outcomes and increased costs. Reconciling penicillin allergies is a necessity to facilitate early, optimal therapy and is a shared responsibility among the healthcare team. Penicillin skin testing (PST) has been utilized successfully in hospitalized patients to de-label erroneous penicillin allergies and optimize antibiotic therapy. This targeted review aims to discuss the practical development and implementation of PST in the inpatient setting. This includes a needs assessment checklist with common considerations allowing for customization to one’s institution based on available personnel, time, and technological resources.

Clinical and Economic Outcomes of Penicillin Skin Testing as an Antimicrobial Stewardship Initiative in a Community Health System

BACKGROUND

Penicillin skin testing (PST) is a novel way to reduce the use of broad-spectrum agents in penicillin-allergic patients. This study evaluated the outcomes of patients with antimicrobials prescribed with and without PST in a community health system.

METHODS

We performed a quasi-experimental study that compared an intervention group of 100 patients who completed PST over an open enrollment period beginning January 2016 with a matched control group of 100 patients who were penicillin allergic. Patients in the control group were matched to infection diagnosis codes of members of the PST group and randomly selected and matched on a 1:1 basis. The primary outcome was noncarbapenem beta-lactam days of therapy (DOT). The secondary outcome assessed the average cost of antimicrobial therapy for the intervention group before and after PST.

RESULTS

Seventy of the 98 patients (71%) who tested negative had changes directly made to their antimicrobial regimens. Beta-lactam DOT for the PST group were 666/1094 (60.88%, with 34.82% being a penicillin specifically). Beta-lactam DOT for the control group consisted of 386/984 (39.64%, with 6.4% being a penicillin specifically). The chi-square test of homogeneity for beta-lactam DOT between the 2 groups was significant (P < .00001). Changes to the antimicrobial regimen after PST saved the average patient $353.03 compared with no change in the pre-PST regimen (P = .045).

CONCLUSIONS

PST led to immediate antimicrobial de-escalation in the majority of patients who tested negative. This led to a significant increase in beta-lactam usage, specifically penicillins. These benefits were also associated with significant cost savings to patients.