Is direct oral amoxicillin challenge a viable approach for 'low-risk' patients labelled with penicillin allergy?

Factors influencing implementation and adoption of direct oral penicillin challenge for allergy delabelling: a qualitative evaluation

BACKGROUND

Over 95% of penicillin allergy labels are inaccurate and may be addressed in low-risk patients using direct oral penicillin challenge (DPC). This study explored the behaviour, attitudes and acceptability of patients, healthcare professionals (HCPs) and managers of using DPC in low-risk patients.

METHODS

Mixed-method, investigation involving patient interviews and staff focus groups at three NHS acute hospitals. Transcripts were coded using inductive and deductive thematic analysis informed by the Theoretical Domains Framework.

FINDINGS

Analysis of 43 patient interviews and three focus groups (28 HCPs: clinicians and managers) highlighted themes of 'knowledge', 'beliefs about capabilities and consequences', 'environmental context', 'resources', 'social influences', 'professional role and identity', 'behavioural regulation and reinforcement' and a cross-cutting theme of digital systems. Overall, study participants supported the DPC intervention. Patients expressed reassurance about being in a monitored, hospital setting. HCPs acknowledged the need for robust governance structures for ensuring clarity of roles and responsibilities and confidence.

CONCLUSION

There were high levels of acceptability among patients and HCPs. HCPs recognised the importance of DPC. Complexities of penicillin allergy (de)labelling were highlighted, and issues of knowledge, risk, governance and workforce were identified as key determinants. These should be considered in future planning and adoption strategies for DPC.

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

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

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

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

Clinical history in suspected cases of immediate allergy to beta-lactam

Background

Mislabeling patients as allergic to beta lactams poses an increased risk of morbidity, healthcare costs, and even mortality. This study aimed to define the accuracy of medical history, taken by a specialist, in diagnosing immediate reaction to beta lactams.

Methods

All patients labeled as allergic to beta lactam were interviewed by a specialist in allergy and clinical immunology and defined as suspected of having a history of immediate or non-immediate reaction. When indicated, skin tests to major and minor determinants and oral graded challenge to the culprit drug were performed.

Results

A total of 909 patients were evaluated. A total of 798 (87.7%) were labeled as allergic to penicillin. In 108 (11.9%) cases, the allergist suspected an immediate reaction based on clinical history. Skin test or challenge proven diagnosis of IgE-mediated allergy to beta lactam were significantly more prevalent in the group with an allergist's suspicion of an immediate allergy (23.1% vs. 5%, p < 0.01). The sensitivity and negative predictive values of an anamnesis of immediate reaction were high (0.9 and 0.95, respectively), but the specificity and positive predictive value were low (0.37 and 0.23, respectively).

Conclusion

Medical history taken by an allergist can exclude immediate hypersensitivity reaction, but it is not specific enough to confirm the diagnosis. Skin testing and graded challenge in suspected cases of immediate hypersensitivity reaction are indicated.

The role of a clinical pharmacist in spurious Penicillin allergy: a narrative review

Background A label of penicillin allergy is held by 6-10% of the general population and 15-20% of inpatients. > 90% of these labels are found to be spurious after formal allergy assessment. Carrying an unnecessary label of penicillin allergy is not benign. Such patients may receive second line, more expensive antibiotics, representing a significant impediment to antimicrobial stewardship. Aim of the review To (a) Explain the burden of spurious penicillin allergy, and evaluate the safety of direct oral penicillin challenge in 'low risk' patients (b) appraise the place for a clinical pharmacist-led penicillin allergy de-labelling programme. Method Narrative review. Search engines: PubMed, Google Scholar and Cochrane reviews. Search criteria: English language; search terms: penicillin allergy, antimicrobial stewardship, antimicrobial resistance, clostridium difficile, vancomycin resistant enterococci, risk stratification, clinical pharmacist and direct oral provocation test Results Penicillin allergy labels are associated with: longer hospital stay, higher readmission rates, enhanced risk of surgical site infections, risk of Clostridioides difficile infection and Methicillin resistant Staphylococcus aureus infection, a delay in the first dose of an antibiotic in sepsis and higher healthcare costs. A direct oral penicillin challenge in 'low risk' patients has proven to be safe. Discussion Recent studies including those led by a clinical pharmacist have demonstrated safety of a direct oral penicillin challenge in 'low risk' patients. This intervention needs validation within individual health services. Conclusion Direct oral penicillin challenge reduces the adverse impact of spurious penicillin allergy. A pharmacist-led penicillin allergy de-labelling program needs further validation in prospective multi-centre studies.

Sustaining and spreading penicillin allergy delabelling: A narrative review of the challenges for service delivery and patient safety

Many patients report allergies to penicillin, although in over 90% of these the label of penicillin allergy is shown to be incorrect following comprehensive testing. Inappropriate and inaccurate penicillin allergy labelling is a barrier to antimicrobial stewardship and can lead to patient harm. This review assesses an emergent evidence base and trend favouring delabelling using direct oral penicillin challenges following a stratified risk assessment of the likelihood and existence of true penicillin allergy, to identify and make recommendations for key components for implementation in standard practice. Research to date has focussed on the feasibility and clinical and financial outcomes of these direct delabelling strategies. There is a paucity of studies exploring the views and engagement of patients and healthcare professionals, and a gap in the evidence for prerequisites to safely deliver, sustain and spread the implementation of such services across health systems.

Antimicrobial Stewardship Interventions to Combat Antibiotic Resistance: an Update on Targeted Strategies

PURPOSE OF REVIEW

Overutilization of antimicrobials is a known contributor to the development of antimicrobial resistance, which is a threat to global health. The goal of antimicrobial stewardship programs (ASPs) is to implement targeted interventions to reduce inappropriate antimicrobial prescribing and prevent development of antimicrobial resistance. We aim to review recently published literature focused on five categories of ASP interventions that have demonstrated success in optimizing appropriate antimicrobial use, improving patient outcomes, and fighting antimicrobial resistance.

RECENT FINDINGS

In the past year, ASP interventions in the published literature have focused on minimizing duration of antimicrobial therapy for infectious syndromes, implementing novel methods for performing prospective audit and feedback, utilizing microbiology laboratory or rapid diagnostic tests to expedite diagnosis, leveraging clinical decision support and electronic medical record tools, and performing penicillin allergy assessment. While the majority of studies assessing ASP interventions do not assess changes in antimicrobial resistance, outcomes demonstrating improved appropriate antibiotic use have been used as a surrogate. Successful ASPs should seek to implement and evaluate novel interventions targeting improvement in antimicrobial prescribing. Such interventions are of critical importance to prevent further growth of antimicrobial resistance.