Penicillin and beta-lactam allergy: epidemiology and diagnosis

Hospitalizations in Children with a Penicillin Allergy Label: An Assessment of Healthcare Impact

BACKGROUND

Beta-lactam allergy is overdiagnosed. Diagnosis of penicillin allergy has been associated with a greater use of hospital resources and an increased risk of antibiotic-resistant infections, although this issue remains poorly studied in children. We aimed to compare patient characteristics and use of hospital resources in hospitalized children with and without a record of penicillin allergy.

METHODS

We identified all hospitalizations in children labelled as being allergic to penicillin in a database containing all hospitalizations in Portuguese public hospitals between 2000 and 2014, and compared these with a similar number of age-, sex-, and main diagnosis-matched hospitalizations without a penicillin allergy label. Comparisons were made for length of hospital stay, comorbidities (Charlson Comorbidity Index), in-hospital mortality, and hospitalization costs.

RESULTS

We identified 1,718 hospitalizations corresponding to children labelled as penicillin-allergic. Compared with patients without such a label, these children had longer hospital stays (mean 5 vs. 4 days, p = 0.03) and a higher comorbidity index (mean 0.11 vs. 0.09, p < 0.001). Hospitalization costs were also higher (EUR 2,071 vs. 1,798), but the difference was not significant (p = 0.12).

CONCLUSIONS

Hospitalizations of children labelled as allergic to penicillin are associated with longer hospital stays, more comorbidities, and a tendency towards higher hospitalization costs. An accurate diagnosis of penicillin allergy based on clinical history and confirmatory tests is therefore essential in all paediatric patients.

IVTH BRAZILIAN CONSENSUS CONFERENCE ON HELICOBACTER PYLORI INFECTION

ABSTRACT Significant progress has been obtained since the III Brazilian Consensus Conference on H. pylori infection held in 2012, in Bento Gonçalves, Brazil, and justify a fourth meeting to establish updated guidelines on the current management of H. pylori infection. Therefore, the Núcleo Brasileiro para Estudo do Helicobacter pylori e Microbiota (NBEHPM), association linked to Brazilian Federation of Gastroenterology (FBG) held its fourth meeting again in Bento Gonçalves, RS, Brazil, on August 25-27, 2017. Twenty-six delegates, including gastroenterologists, endoscopists, and pathologists from the five regions of Brazil as well as one international guest from the United States, participated in the meeting. The participants were invited based on their knowledge and contribution to the study of H. pylori infection. The meeting sought to review different aspects of treatment for infection; establish a correlation between infection, dyspepsia, intestinal microbiota changes, and other disorders with a special emphasis on gastric cancer; and reassess the epidemiological and diagnostic aspects of H. pylori infection. Participants were allocated into four groups as follows: 1) Epidemiology and Diagnosis, 2) Dyspepsia, intestinal microbiota and other afections, 3) Gastric Cancer, and, 4) Treatment. Before the consensus meeting, participants received a topic to be discussed and prepared a document containing a recent literature review and statements that should be discussed and eventually modified during the face-to-face meeting. All statements were evaluated in two rounds of voting. Initially, each participant discussed the document and statements with his group for possible modifications and voting. Subsequently, during a second voting in a plenary session in the presence of all participants, the statements were voted upon and eventually modified. The participants could vote using five alternatives: 1) strongly agree; 2) partially agree; 3) undecided; 4) disagree; and 5) strongly disagree. The adopted consensus index was that 80% of the participants responded that they strongly or partially agreed with each statement. The recommendations reported are intended to provide the most current and relevant evidences to management of H. pylori infection in adult population in Brazil.

Influence of Reported Penicillin Allergy on Mortality in MSSA Bacteremia

Background

Penicillin allergy frequently impacts antibiotic choice. As beta-lactams are superior to vancomycin in treating methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia, we examined the effect of reported penicillin allergy on clinical outcomes in patients with MSSA bacteremia.

Methods

In this retrospective cohort study of adults with MSSA bacteremia admitted to a large tertiary care hospital, outcomes were examined according to reported penicillin allergy. Primary outcomes included 30-day and 90-day mortality rates. Multivariable regression models were developed to quantify the effect of reported penicillin allergy on mortality while adjusting for potential confounders.

Results

From 2010 to 2015, 318 patients with MSSA bacteremia were identified. Reported penicillin allergy had no significant effect on adjusted 30-day mortality (odds ratio [OR], 0.73; 95% confidence interval [CI], 0.29-1.84; P = .51). Patients with reported penicillin allergy were more likely to receive vancomycin (38% vs 11%, P < .01), but a large number received cefazolin regardless of reported allergy (29 of 66, 44%). Mortality rates were highest among nonallergic patients receiving vancomycin (22.6% vs 7.4% for those receiving beta-lactams regardless of reported allergy, P < .01). In multivariable analysis, beta-lactam receipt was most strongly associated with survival (OR, 0.26; 95% CI, 0.12-0.54).

Conclusions

Reported penicillin allergy had no significant effect on 30- or 90-day mortality. Non-penicillin-allergic patients receiving vancomycin for treatment of MSSA bacteremia had the highest mortality rates overall. Receipt of a beta-lactam was the strongest predictor of survival. These results underscore the importance of correct classification of patients with penicillin allergy and appropriate treatment with a beta-lactam when tolerated.

Do Postoperative Antibiotics Decrease the Frequency of Inflammatory Complications Following Third Molar Removal?

PURPOSE

The purpose of this study was to answer the following clinical question: among patients who have their third molars (M3s) removed, do those who receive only postoperative antibiotics compared with those who receive no perioperative antibiotics have a lower frequency of postoperative inflammatory complications?

MATERIALS AND METHODS

The authors designed and implemented a prospective cohort study and enrolled a sample of patients who had at least 1 M3 removed in an ambulatory private practice setting from June 2011 through May 2012 by oral and maxillofacial surgeons participating in a practice-based research collaborative. The predictor variable was postoperative antibiotic use categorized as postoperative antibiotics alone or no antibiotics. The primary outcome variable was the presence or absence of an inflammatory complication (ie, alveolar osteitis or surgical site infection) after M3 removal. Descriptive, bivariate, and multiple logistic regression statistics (adjusted for clustering within surgical practices) were computed to measure the association between postoperative antibiotic use alone and inflammatory complications after M3 removal, with statistical significance set at a P value less than or equal to .05.

RESULTS

The study sample was composed of 1,877 patients having 5,631 M3s removed, of which 61% received postoperative antibiotics only. The overall inflammatory complication frequencies in the groups receiving postoperative antibiotic only and no antibiotic were 4.3 and 7.5%, respectively (P = .003). After adjusting for differences between the 2 study groups and clustering of patients within surgical practices, postoperative antibiotic use was associated with a 40% decreased risk of developing postoperative inflammatory complications (P = .04) with marginal statistical significance.

CONCLUSIONS

The results of this study suggest that postoperative antibiotic therapy is associated with a statistically meaningful decreased risk of inflammatory complications after M3 removal compared with no antibiotic therapy.

Assembled growth of 3D Fe3O4@Au nanoparticles for efficient photothermal ablation and SERS detection of microorganisms

A leukocyte-like Fe₃O₄@Au-polydopamine nanohybrid performed a magnetism-based enhanced SERS signal and efficient NIR-irradiated photothermal antibacterial agent.

Evaluation and Management of Penicillin Allergy

Penicillin allergy is the most commonly reported drug allergy in the United States. Although penicillin allergy is widely reported, 80% to 90% of individuals with self-reported penicillin allergy are actually able to tolerate penicillins after undergoing evaluation for penicillin allergy. Because most patients with self-reported penicillin allergy will have subsequent negative allergy testing results and tolerate penicillins, they may be unnecessarily exposed to broader-spectrum antibiotics. Use of such antibiotics leads to increased risks of developing antibiotic-resistant microorganisms and incur higher health care utilization costs. In this article, we provide an overview of penicillin allergy and its clinical manifestations as well as an approach for the evaluation and management of penicillin allergy.

Diagnosing and managing patients with drug hypersensitivity

INTRODUCTION

Diagnosing and managing drug hypersensitivity is challenging because there are no clear limits between different types of drug reactions. Distinguishing between type A (predictable) and type B (hypersensitivity) reactions when a drug is introduced on the market is not easy. When many people use a drug, adverse reactions can occur, conditioned by diverse genetic profiles, viral infections or concomitant therapy. Occasionally the only tool clinicians have on which to base the diagnosis is the clinical history. Skins tests or in vitro tests sometimes have low sensitivity or are unavailable, and drug provocation tests may be dangerous or strictly forbidden in case of severe cutaneous reactions. Areas covered: This paper reviews the diagnosis and management of the two main types of immunological reactions: IgE-mediated immediate drug hypersensitivity reactions (IDHRs) and non-immediate drug hypersensitivity reactions (NIDHRs). Expert commentary: Although Europe and the United States use different diagnostic methods, patients with history of drug hypersensitivity must avoid the suspicious drug, and clinicians must assess tolerance to safe alternatives under medical surveillance. Sometimes desensitization may be required. There is a consensus about the need to perform genetic testing for specific drugs and give patients proper documentation to prevent future exposure to culprit drugs.

Variation in prophylactic antibiotic use for laparoscopic cholecystectomy: need for better stewardship in pediatric surgery

PURPOSE

The role of prophylactic antibiotics for elective laparoscopic cholecystectomy has been questioned over the last decade. Although gradually being discontinued in the adult population, the practice among pediatric surgeons remains unknown. Our aim was to investigate the use of perioperative antibiotics in children undergoing elective laparoscopic cholecystectomy (LC) for symptomatic cholelithiasis and biliary dyskinesia.

METHODS

We retrospectively reviewed the Pediatric Health Information System (PHIS) database for 2015 and selected all patients 18years old or younger who underwent LC for cholelithiasis (without cholecystitis) or biliary dyskinesia. Demographic and hospital data were extracted as well as antibiotics administered and surgical complications.

RESULTS

A total of 1112 patients from 44 hospitals were identified with a median age of 15years (IQR 13-16years). Eight out of every 10 hospitals routinely give prophylactic antibiotics in more than 50% of patients. In 37 hospitals that performed more than 5 LC per year, 19 to 100% of patients were given antibiotics. No surgical complications were identified in those who did not get antibiotics.

CONCLUSION

There is significant inter-hospital variation in prophylactic antibiotic administration for elective LC in children. Perioperative antibiotic administration should be tracked as a quality metric in the current push for better stewardship.

LEVEL OF EVIDENCE

III.

TYPE OF STUDY

Retrospective.

Cross-reactivity in β-Lactam Allergy

β-Lactam drugs (penicillins, amoxicillin, and cephalosporins) account for 42.6% of all severe drug-induced anaphylaxis. In this review, we focus on clinically significant immunologic cross-reactivity in patients with confirmed penicillin allergy to cephalosporins, and the structural involvement of the R₁ and R₂ chemical side chains of the cephalosporins causing IgE-mediated cross-reactivity with penicillin and other cephalosporins. Skin tests predict IgE-mediated reactions and showed cross-reactivity between penicillins and early generation cephalosporins that shared side chains, but confirmatory challenge data are lacking. Later-generation cephalosporins, which have distinct side chains, do not have any skin test cross-reactivity with penicillin/amoxicillin. There is debate as to the involvement of R₂ side chains as the antigenic determinants that cause IgE-mediated hypersensitivity with various cephalosporins. Avoidance of cephalosporins, when they are the drug of choice in a penicillin-allergic individual, results in significant morbidity that outweighs the low risk of anaphylaxis. We conclude that there is ample evidence to allow the safe use of cephalosporins in patients with isolated confirmed penicillin or amoxicillin allergy.

Evaluation of Penicillin Allergy in the Hospitalized Patient: Opportunities for Antimicrobial Stewardship

PURPOSE OF REVIEW

Penicillin allergy is often misdiagnosed and is associated with adverse consequences, but testing is infrequently done in the hospital setting. This article reviews historical and contemporary innovations in inpatient penicillin allergy testing and its impact on antimicrobial stewardship.

RECENT FINDINGS

Adoption of the electronic medical record allows rapid identification of admitted patients carrying a penicillin allergy diagnosis. Collaboration with clinical pharmacists and the development of computerized clinical guidelines facilitates increased testing and appropriate use of penicillin and related β-lactams. Education of patients and their outpatient providers is the key to retaining the benefits of penicillin allergy de-labeling. Penicillin allergy testing is feasible in the hospital and offers tangible benefits towards antimicrobial stewardship. Allergists should take the lead in this endeavor and work towards overcoming personnel limitations by partnering with other health care providers and incorporating technology that improves the efficiency of allergy evaluation.

Antibiotic prophylaxis is not indicated prior to dental procedures for prevention of periprosthetic joint infections

Background and purpose - To minimize the risk of hematogenous periprosthetic joint infection (HPJI), international and Dutch guidelines recommended antibiotic prophylaxis prior to dental procedures. Unclear definitions and contradictory recommendations in these guidelines have led to unnecessary antibiotic prescriptions. To formulate new guidelines, a joint committee of the Dutch Orthopaedic and Dental Societies conducted a systematic literature review to answer the following question: can antibiotic prophylaxis be recommended for patients (with joint prostheses) undergoing dental procedures in order to prevent dental HPJI? Methods - The Medline, Embase, and Cochrane databases were searched for randomized controlled trials (RCTs), reviews, and observational studies up to July 2015. Studies were included if they involved patients with joint implants undergoing dental procedures, and either considered HPJI as an outcome measure or described a correlation between HPJI and prophylactic antibiotics. A guideline was formulated using the GRADE method and AGREE II guidelines. Results - 9 studies were included in this systematic review. All were rated "very low quality of evidence". Additional literature was therefore consulted to address clinical questions that provide further insight into pathophysiology and risk factors. The 9 studies did not provide evidence that use of antibiotic prophylaxis reduces the incidence of dental HPJI, and the additional literature supported the conclusion that antibiotic prophylaxis should be discouraged in dental procedures. Interpretation - Prophylactic antibiotics in order to prevent dental HPJI should not be prescribed to patients with a normal or an impaired immune system function. Patients are recommended to maintain good oral hygiene and visit the dentist regularly.

The revolving door: antibiotic allergy labelling in a tertiary care centre

BACKGROUND

Patients frequently report antibiotic allergies; however, only 10% of labelled patients have a true allergy.

AIM

We investigated the documentation of antibiotic 'allergy' labels (AAL) and the effect of labelling on clinical outcomes, in a West Australian adult tertiary hospital.

METHODS

Retrospective cross-sectional analysis of patients captured in the 2013 and 2014 National Antimicrobial Prescribing Surveys was carried out. Data were collected on documented antibiotic adverse drug reactions, antibiotic cost, prescribing appropriateness, prevalence of multi-drug resistant organisms, length of stay, intensive care admission and readmissions.

RESULTS

Of the 687 patients surveyed, 278 (40%) were aged 70 or above, 365 (53%) were male and 279 (41%) were prescribed antibiotics. AAL were recorded in 122 (18%) patients and the majority were penicillin labels (n = 87; 71%). Details of AAL were documented for 80 of 141 (57%) individual allergy labels, with 61 describing allergic symptoms. Patients with beta-lactam allergy labels received fewer penicillins (P = 0.0002) and more aminoglycosides (P = 0.043) and metronidazole (P = 0.021) than patients without beta-lactam labels. Five patients received an antibiotic that was contraindicated according to their allergy status. Patients with AAL had significantly more hospital readmissions within 4 weeks (P = 0.001) and 6 months (P = 0.025) of discharge, compared with unlabelled patients. The majority (81%) of readmitted labelled patients had major infections.

CONCLUSIONS

AAL are common, but poorly documented in hospital records. Patients with AAL are significantly more likely to require alternative antibiotics and hospital readmissions. There may be a role for antibiotic allergy delabelling to mitigate the clinical and economic burdens for patients with invalid allergy labels.

Impact of an Integrated Antibiotic Allergy Testing Program on Antimicrobial Stewardship: A Multicenter Evaluation

Background

Despite the high prevalence of patient-reported antibiotic allergy (so-called antibiotic allergy labels [AALs]) and their impact on antibiotic prescribing, incorporation of antibiotic allergy testing (AAT) into antimicrobial stewardship (AMS) programs (AAT-AMS) is not widespread. We aimed to evaluate the impact of an AAT-AMS program on AAL prevalence, antibiotic usage, and appropriateness of prescribing.

Methods

AAT-AMS was implemented at two large Australian hospitals during a 14-month period beginning May 2015. Baseline demographics, AAL history, age-adjusted Charlson comorbidity index, infection history, and antibiotic usage for 12 months prior to testing (pre-AAT-AMS) and 3 months following testing (post-AAT-AMS) were recorded for each participant. Study outcomes included the proportion of patients who were "de-labeled" of their AAL, spectrum of antibiotic courses pre- and post-AAT-AMS, and antibiotic appropriateness (using standard definitions).

Results

From the 118 antibiotic allergy-tested patients, 226 AALs were reported (mean, 1.91/patient), with 53.6% involving 1 or more penicillin class drug. AAT-AMS allowed AAL de-labeling in 98 (83%) patients-56% (55/98) with all AALs removed. Post-AAT, prescribing of narrow-spectrum penicillins was more likely (adjusted odds ratio [aOR], 2.81, 95% confidence interval [CI], 1.45-5.42), as was narrow-spectrum β-lactams (aOR, 3.54; 95% CI, 1.98-6.33), and appropriate antibiotics (aOR, 12.27; 95% CI, 5.00-30.09); and less likely for restricted antibiotics (aOR, 0.16; 95% CI, .09-.29), after adjusting for indication, Charlson comorbidity index, and care setting.

Conclusions

An integrated AAT-AMS program was effective in both de-labeling of AALs and promotion of improved antibiotic usage and appropriateness, supporting the routine incorporation of AAT into AMS programs.

Vonoprazan improves the efficacy of Helicobacter pylori eradication therapy with a regimen consisting of clarithromycin and metronidazole in patients allergic to penicillin

BACKGROUND

Although all Helicobacter pylori (H. pylori)-positive patients should receive eradication therapy, the therapy is a challenge for patients allergic to penicillin. There have been a few reports on the efficacy of eradication therapy for such patients.

OBJECTIVE

To analyze the efficacy of vonoprazan or proton pump inhibitor (PPI)-based 7-day triple therapy in patients allergic to penicillin.

MATERIALS AND METHODS

A total of 88 consecutive patients allergic to penicillin who received H. pylori eradication therapy were retrospectively analyzed. Thirty-one patients had a history of failed eradication therapy. Four 7-day regimens were prescribed during the study period: clarithromycin-metronidazole-PPI (13 patients), clarithromycin-metronidazole-vonoprazan (14 patients), metronidazole-sitafloxacin-PPI (44 patients) and metronidazole-sitafloxacin-vonoprazan (17 patients). A ¹³ C-urea breath test was used for confirmation of eradication, and efficacy of eradication was evaluated by "intention-to-treat" analysis and "per-protocol" analysis.

RESULTS

Intention-to-treat and per-protocol eradication rates were 46.2%/54.6% for patients who received clarithromycin-metronidazole-PPI, 92.9/92.9% for patients who received clarithromycin-metronidazole-vonoprazan, 100/100% for patients who received metronidazole-sitafloxacin-PPI and 88.2/93.8% for patients who received metronidazole-sitafloxacin-vonoprazan. For first eradication, vonoprazan significantly raised the intention-to-treat efficacy of the triple therapy including clarithromycin-metronidazole (vonoprazan: 92.9%, PPI: 46.2%, P=.0128). A 7-day regimen consisting of metronidazole and sitafloxacin was effective for patients allergic to penicillin with or without past failure of eradication.

CONCLUSION

For first eradication in patients allergic to penicillin, a 7-day triple therapy consisting of clarithromycin, metronidazole and vonoprazan could be a candidate eradication regimen.

Second generation cephalosporin antibiotic prophylaxis and Clostridium difficile infection in hip and knee arthroplasty

Introduction The use of broad spectrum cephalosporin antibiotics has been discouraged by the Department of Health in England because of the link to increased Clostridium difficile infection rates. The aim of this study was to evaluate whether a local protocol that included the use of second generation cephalosporin (cefuroxime) antibiotics as a prophylactic agent was associated with increased risk of C difficile in elective hip and knee arthroplasty patients. Methods A retrospective intention-to-treat study was conducted. An infection control database of all cases of C difficile infection both in hospital and in the community was reviewed and cross-referenced against surgical records. A positive correlation was identified when a C difficile positive sample was documented within eight weeks of arthroplasty surgery. Results Only 1 case (0.02%) of C difficile positive diarrhoea was identified that correlated to the 8-week postoperative period following 4,488 arthroplasty procedures. Conclusions The use of cephalosporin antibiotic prophylaxis in the elective hip and knee arthroplasty setting does not appear to be associated with increased C difficile infection rates, achieving surgical site infection rates that are comparable with the national average.

Amoxicillin haptenates intracellular proteins that can be transported in exosomes to target cells

BACKGROUND

Allergic reactions to β-lactams are among the most frequent causes of drug allergy and constitute an important clinical problem. Drug covalent binding to endogenous proteins (haptenation) is thought to be required for activation of the immune system. Nevertheless, neither the nature nor the role of the drug protein targets involved in this process is fully understood. Here, we aim to identify novel intracellular targets for haptenation by amoxicillin (AX) and their cellular fate.

METHODS

We have treated B lymphocytes with either AX or a biotinylated analog (AX-B). The identification of protein targets for haptenation by AX has been approached by mass spectrometry and immunoaffinity techniques. In addition, intercellular communication mediated by the delivery of vesicles loaded with AX-B-protein adducts has been explored by microscopy techniques.

RESULTS

We have observed a complex pattern of AX-haptenated proteins. Several novel targets for haptenation by AX in B lymphocytes have been identified. AX-haptenated proteins were detected in cell lysates and extracellularly, either as soluble proteins or in lymphocyte-derived extracellular vesicles. Interestingly, exosomes from AX-B-treated cells showed a positive biotin signal in electron microscopy. Moreover, they were internalized by endothelial cells, thus supporting their involvement in intercellular transfer of haptenated proteins.

CONCLUSIONS

These results represent the first identification of AX-mediated haptenation of intracellular proteins. Moreover, they show that exosomes can constitute a novel vehicle for haptenated proteins, and raise the hypothesis that they could provide antigens for activation of the immune system during the allergic response.

Feasibility, Benefits, and Limitations of a Penicillin Allergy Skin Testing Service

OBJECTIVE

To critically examine the feasibility, benefits, and limitations of an inpatient penicillin skin testing service and how pharmacists can be utilized.

DATA SOURCES

A PubMed search was performed from July 2016 through September 2016 using the following search terms: penicillin skin testing, penicillin allergy, β-lactam allergy. Additional references were identified from a review of literature citations.

STUDY SELECTION AND DATA EXTRACTION

All English-language studies assessing the use of penicillin skin testing as well as management and clinical outcomes of patients with a β-lactam allergy were evaluated.

DATA SYNTHESIS

The prevalence of people self-identifying as penicillin allergic ranges from 10% to 20% in the United States. Being improperly labeled as penicillin allergic is associated with higher health care costs, worse clinical outcomes, and an increased prevalence of multidrug-resistant infections. Penicillin skin testing can be a tool used to clarify penicillin allergies and has been demonstrated to be a successful addition to antimicrobial stewardship programs in multiple health care settings. Prior to implementing a penicillin skin testing service, institutions will need to perform a feasibility analysis of who will supply labor and accept the financial burden as well as identify if the positive benefits of a penicillin skin testing service overcome the limitations of this diagnostic test.

CONCLUSION

We conclude that institutions with high percentages of patients receiving non-β-lactams because of penicillin allergy labels would likely benefit the most from a penicillin skin testing service.

Morbidity in Pregnant Women Associated with Unverified Penicillin Allergies, Antibiotic Use, and Group B Streptococcus Infections

CONTEXT

The morbidity potentially associated with unverified penicillin allergy in pregnant women, with and without group B streptococcus (GBS) infections, is unknown. Penicillin allergy testing is safe during pregnancy but is done infrequently.

OBJECTIVE

To determine morbidity associated with antibiotic use in a large cohort of pregnant women, with and without an unverified history of penicillin allergy, and with and without GBS.

DESIGN

Retrospective. All pregnant women who delivered live infants in Kaiser Permanente Southern California between January 1, 2009, and December 31, 2014, were identified.

MAIN OUTCOME MEASURES

Penicillin allergy status at delivery, delivery method, maternal and infant hospital utilization, peripartum antibiotic exposures, new antibiotic-associated adverse drug reactions, and new Clostridium difficile infections.

RESULTS

There were 170,379 unique women who had 201,316 pregnancies during the study period. There were 16,084 pregnancies in women with an active, but unverified, penicillin allergy at delivery. There were 42,524 pregnancies in GBS-positive women, and 3500 also had a penicillin allergy. Women with a penicillin allergy, with or without GBS, had significantly (about 10%) higher cesarean section rates and spent significantly more (about 0.1) days in the hospital after delivery. Among GBS-positive women, those with an unverified penicillin allergy were exposed to significantly more cefazolin, clindamycin, vancomycin, and gentamicin and had significantly higher rates of adverse drug reactions associated with all antibiotic use.

CONCLUSIONS

Unverified penicillin allergy is associated with more hospital utilization and additional morbidity. Penicillin allergy testing of pregnant women with a history of penicillin allergy may help reduce these unwanted outcomes.

Return to sender: the need to re-address patient antibiotic allergy labels in Australia and New Zealand

BACKGROUND/AIM

Antibiotic allergies are frequently reported and have significant impacts upon appropriate prescribing and clinical outcomes. We surveyed infectious diseases physicians, allergists, clinical immunologists and hospital pharmacists to evaluate antibiotic allergy knowledge and service delivery in Australia and New Zealand.

METHODS

An online multi-choice questionnaire was developed and endorsed by representatives of the Australasian Society of Clinical Immunology and Allergy (ASCIA) and the Australasian Society of Infectious Diseases (ASID). The 37-item survey was distributed in April 2015 to members of ASCIA, ASID, the Society of Hospital Pharmacists of Australia and the Royal Australasian College of Physicians.

RESULTS

Of 277 respondents, 94% currently use or would utilise antibiotic allergy testing (AAT) and reported seeing up to 10 patients/week labelled as antibiotic-allergic. Forty-two per cent were not aware of or did not have AAT available. Most felt that AAT would aid antibiotic selection, antibiotic appropriateness and antimicrobial stewardship (79, 69 and 61% respectively). Patients with the histories of immediate hypersensitivity were more likely to be referred than those with delayed hypersensitivities (76 vs 41%, P = 0.0001). Lack of specialist physicians (20%) and personal experience (17%) were barriers to service delivery. A multidisciplinary approach was a preferred AAT model (53%). Knowledge gaps were identified, with the majority overestimating rates of penicillin/cephalosporin (78%), penicillin/carbapenem (57%) and penicillin/monobactam (39%) cross-reactivity.

CONCLUSIONS

A high burden of antibiotic allergy labelling and demand for AAT is complicated by a relative lack availability or awareness of AAT services in Australia and New Zealand. Antibiotic allergy education and deployment of AAT, accessible to community and hospital-based clinicians, may improve clinical decisions and reduce antibiotic allergy impacts. A collaborative approach involving infectious diseases physicians, pharmacists and allergists/immunologists is required.

Improving Antimicrobial Stewardship by Antibiotic Allergy Delabeling: Evaluation of Knowledge, Attitude, and Practices Throughout the Emerging Infections Network

Antibiotic allergy testing (AAT) practices of Emerging Infections Network infectious disease physicians were surveyed. Although AAT was perceived to be necessary for removal of inappropriate or unnecessary allergy labels, there was limited access to any form of testing. In this study, we discuss current antibiotic allergy knowledge gaps and the development of AAT practices within antimicrobial stewardship programs, which will potentially improve antimicrobial prescribing.

Special endpoint and product specific considerations in pharmaceutical acceptable daily exposure derivation

Recently, a guideline has been published by the European Medicines Agency (EMA) on setting safe limits, permitted daily exposures (PDE) [also called acceptable daily exposures (ADE)], for medicines manufactured in multi-product facilities. The ADE provides a safe exposure limit for inadvertent exposure of a drug due to cross-contamination in manufacturing. The ADE determination encompasses a standard risk assessment, requiring an understanding of the toxicological and pharmacological effects, the mechanism of action, drug compound class, and the dose-response as well as the pharmacokinetic properties of the compound. While the ADE concept has broad application in pharmaceutical safety there are also nuances and specific challenges associated with some toxicological endpoints or drug product categories. In this manuscript we discuss considerations for setting ADEs when the following specific adverse health endpoints may constitute the critical effect: genotoxicity, developmental and reproductive toxicity (DART), and immune system modulation (immunostimulation or immunosuppression), and for specific drug classes, including antibody drug conjugates (ADCs), emerging medicinal therapeutic compounds, and compounds with limited datasets. These are challenging toxicological scenarios that require a careful evaluation of all of the available information in order to establish a health-based safe level.

Practical Management of Patients with a History of Immediate Hypersensitivity to Common non-Beta-Lactam Drugs

Immediate hypersensitivity reactions to medications are among the most feared adverse drug reactions, because of their close association with anaphylaxis. This review discusses a practical management approach for patients with a history of an immediate hypersensitivity to a non-beta-lactam medication, where reexposure to the implicated, or similar, medication is clinically necessary. Mechanisms associated with severe immediate hypersensitivity reactions include IgE-mediated mast cell activation, complement-mediated mast cell activation, and direct mast cell activation. Immediate hypersensitivity reactions may also be mediated by vasodilators, other pharmacologic mechanisms, or be secondary to underlying patient-specific biochemical abnormalities such as endocrine tumors or chronic spontaneous urticaria. The key features in the reaction history and the biochemistry of the implicated medication are discussed. Most individuals with a history of immediate hypersensitivity to a medication, who require reuse of that drug, can be safely retreated with a therapeutic course of the implicated drug after a full-dose challenge, graded challenge, or desensitization, with or without premedication and/or any preliminary diagnostic testing, depending on the specific situation.

Antimicrobial allergy 'labels' drive inappropriate antimicrobial prescribing: lessons for stewardship

BACKGROUND

The presence of antimicrobial allergy designations ('labels') often substantially reduces prescribing options for affected patients, but the frequency, accuracy and impacts of such labels are unknown.

METHODS

The National Antimicrobial Prescribing Survey (NAPS) is an annual de-identified point prevalence audit of Australian inpatient antimicrobial prescribing using standardized definitions of guideline compliance, appropriateness and indications. Data were extracted for 2 years (2013-14) and compared for patients with an antimicrobial allergy label (AAL) and with no AAL (NAAL).

RESULTS

Among 21 031 patients receiving antimicrobials (33 421 prescriptions), an AAL was recorded in 18%, with inappropriate antimicrobial use significantly higher in the AAL group versus the NAAL group (OR 1.12, 95% CI 1.05-1.22, P < 0.002). Patterns of antimicrobial use were significantly influenced by AAL, with lower β-lactam use (AAL versus NAAL; OR 0.47, 95% CI 0.43-0.50, P < 0.001) and higher quinolone (OR 2.07, 95% CI 1.83-2.34, P < 0.0001), glycopeptide (OR 1.59, 95% CI 1.38-1.83, P < 0.0001) and carbapenem (OR 1.74, 95% CI 1.43-2.13, P < 0.0001) use. In particular, among immunocompromised patients, AAL was associated with increased rates of inappropriate antimicrobial use (OR 1.68, 95% CI 1.21-2.30, P = 0.003), as well as increased use of quinolones (OR 1.88, 95% CI 1.16-3.03, P = 0.02) and glycopeptides (OR 1.82, 95% CI 1.17-2.84, P = 0.01).

CONCLUSIONS

AALs are common and appear to be associated with higher rates of inappropriate prescribing and increased use of broad-spectrum antimicrobials. Improved accuracy in defining AALs is likely to be important for effective antimicrobial stewardship (AMS), with efforts to 'de-label' inappropriate AAL patients a worthwhile feature of future AMS initiatives.

The prevalence and impact of antimicrobial allergies and adverse drug reactions at an Australian tertiary centre

Background

The prevalence and impact of antimicrobial “allergy” labels and Adverse Drug Reactions (ADRs) on antibiotic usage and antimicrobial stewardship initiatives is ill defined. We sought to examine the rate of antimicrobial “allergy labels” at our tertiary referral centre and impacts on antimicrobial usage and appropriateness.

Methods

Two inpatient antimicrobial prevalence surveys were conducted over a 1-week period in November 2013 and 2014 as part of the prospective National Antimicrobial Prescribing Survey (NAPS). Post survey, patients recorded in the NAPS database were assigned to two groups based upon recorded antimicrobial “allergy label” and ADR: (i) Antimicrobial Allergy/ADR (AA) or (ii) No Antimicrobial Allergy/ADR (NAA). Antimicrobial usage and antimicrobial appropriateness were compared between AA and NAA groups.

Results

From 509 identified patients the prevalence of an antimicrobial allergy or ADR was 25 %. The prevalence of “allergy labels”/ADR was 10 % (51/509) for penicillin V/G, 5 % (24/509) cephalosporins, 4 % (22/509) trimethroprim-sulfamethoxazole and 3 % (17/509) aminopenicillins. One thousand and seventy antimicrobials were prescribed during the study periods, the median antimicrobial duration was longer in the AA versus NAA group (6 days vs. 4 days; p = 0.018), and proportion of inappropriate antimicrobial prescribing higher in the AA group compared with NAA (29 %; 35/120 vs. 23 %; 86/367, p = 0.22). Oral antimicrobial administration was higher in the NAA than AA group (60 %; 177/297 vs. 46 %; 356/793, p = 0.0001). The proportion of patients that received a β-lactam was lower in the AA versus NAA group (60 % vs. 79 %, p = 0.0001).

Conclusions

In an Australian tertiary referral centre an antimicrobial “allergy” or ADR label was found to significantly impacted on rate of oral antimicrobial administration, beta-lactam usage, antimicrobial duration and antimicrobial appropriateness.

Identifying opportunities in EHR to improve the quality of antibiotic allergy data

BACKGROUND

Antimicrobial resistance is a growing, global public health crisis, due in large part to the overuse and misuse of antibiotics. Understanding medication allergy data and allergy reactions that are documented in electronic health records (EHRs) can help to identify opportunities to improve the quality of documentation of beta-lactam allergies, thus potentially reducing the prescribing of alternative antibiotics.

METHODS

Medication allergies and allergy reactions recorded in the EHR for 319 051 patients seen across 32 community health centers were reviewed. Patients with a beta-lactam allergy recorded in their EHR were identified. Free text, as well as standardized allergy and allergy reaction fields, were analyzed.

RESULTS

Among patients, 9.1% (n = 29 095) had evidence of a beta-lactam allergy recorded in their EHR. Women, white, and non-Hispanic patients were more likely to have a documented allergy compared to men, black, and Hispanic patients. Among all patients with a documented beta-lactam allergy, 36.2% had an empty or missing allergy reaction description in their EHR.

CONCLUSIONS

Findings suggest that current EHR documentation practices among the health centers reviewed do not provide enough information on allergic reactions to allow providers to discern between true allergies and common, but anticipated, drug side effects. Improved EHR documentation guidance, training that reinforces the use of standardized data and more detailed recording of allergic reactions, combined with initiatives to address patient barriers including health literacy, may help to improve the accuracy of drug allergies in patients' records. These initiatives, combined with antimicrobial stewardship programs, can help to reduce inappropriate prescribing of alternative antibiotics when beta-lactam antibiotics are first-line and can be tolerated.

Report from the National Institute of Allergy and Infectious Diseases workshop on drug allergy

Allergic reactions to drugs are a serious public health concern. In 2013, the Division of Allergy, Immunology, and Transplantation of the National Institute of Allergy and Infectious Diseases sponsored a workshop on drug allergy. International experts in the field of drug allergy with backgrounds in allergy, immunology, infectious diseases, dermatology, clinical pharmacology, and pharmacogenomics discussed the current state of drug allergy research. These experts were joined by representatives from several National Institutes of Health institutes and the US Food and Drug Administration. The participants identified important advances that make new research directions feasible and made suggestions for research priorities and for development of infrastructure to advance our knowledge of the mechanisms, diagnosis, management, and prevention of drug allergy. The workshop summary and recommendations are presented herein.

Deficits in allergy knowledge among physicians at academic medical centers

BACKGROUND

Allergic conditions have high prevalence in the general population. Misconceptions regarding the diagnosis and management of allergic disease among physicians can lead to suboptimal clinical care.

OBJECTIVE

To determine the extent of allergy-related knowledge deficits among physicians.

METHODS

Pediatric and internal medicine resident and attending physicians from 2 separate academic medical centers were asked to answer an anonymous electronic survey. Survey questions addressed 7 different allergy content areas.

RESULTS

Four hundred eight physicians completed surveys (23.9% response rate). Respondents had few correct answers (mean ± SD 1.91 ± 1.43). Pediatric respondents had a larger number of correct answers compared with medicine-trained physicians (P < .001). No individual answered every survey question correctly, and 50 respondents (12.3%) had no correct answer. Three hundred seventy-eight respondents (92.6%) were unable to provide correct answers for at least 50% of survey questions. Level of residency training and prior rotation through an allergy and immunology elective correlated with a larger number of correct responses (P < .01). Only 1 survey question had an overall correct response rate higher than 50% (n = 261, 64%). Correct response rate was lower than 30% for 7 of the 9 possible questions.

CONCLUSION

There are significant knowledge deficits in many areas of allergy-related content among pediatric and internal medicine physicians and across all levels of training and specialty. Given the prevalence of allergic conditions, the potential implications of a negative impact on clinical care are staggering.

Incidence and nature of adverse reactions to antibiotics used as endocarditis prophylaxis

OBJECTIVES

Antibiotic prophylaxis (AP) administration prior to invasive dental procedures has been a leading focus of infective endocarditis prevention. However, there have been long-standing concerns about the risk of adverse drug reactions as a result of this practice. The objective of this study was to identify the incidence and nature of adverse reactions to amoxicillin and clindamycin prophylaxis to prevent infective endocarditis.

METHODS

We obtained AP prescribing data for England from January 2004 to March 2014 from the NHS Business Services Authority, and adverse drug reaction data from the Medicines and Healthcare Products Regulatory Agency's Yellow Card reporting scheme for prescriptions of the standard AP protocol of a single 3 g oral dose of amoxicillin or a single 600 mg oral dose of clindamycin for those allergic to penicillin.

RESULTS

The reported adverse drug reaction rate for amoxicillin AP was 0 fatal reactions/million prescriptions (in fact 0 fatal reactions for nearly 3 million prescriptions) and 22.62 non-fatal reactions/million prescriptions. For clindamycin, it was 13 fatal and 149 non-fatal reactions/million prescriptions. Most clindamycin adverse drug reactions were Clostridium difficile infections.

CONCLUSIONS

AP adverse drug reaction reporting rates in England were low, particularly for amoxicillin, and lower than previous estimates. This suggests that amoxicillin AP is comparatively safe for patients without a history of amoxicillin allergy. The use of clindamycin AP was, however, associated with significant rates of fatal and non-fatal adverse drug reactions associated with C. difficile infections. These were higher than expected and similar to those for other doses, durations and routes of clindamycin administration.