Penicillin allergy: a practical approach to assessment and prescribing

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

OBJECTIVE

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

METHOD

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

RESULTS

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

CONCLUSION

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

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

OBJECTIVE

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

METHOD

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

RESULTS

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

CONCLUSION

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

Ethics of antibiotic allergy

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

Penicillin Allergy Impact and Management

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

To prescribe or not to prescribe? A review of the Prescribing Competencies Framework for dentistry

OBJECTIVES

Dentists in Australia are the second largest prescriber group, and are generally not formally taught how to prescribe. The objective of this review is to describe the Prescribing Competencies Framework and its relevance to dentistry.

DATA

The four-model stage of prescribing by Coombes and colleagues, and the seven competencies within the Prescribing Competencies Framework devised by the Australian National Prescribing Service MedicineWise, are discussed and applied to dentistry.

SOURCES AND STUDY SELECTION

Each of the seven competencies are analysed and detailed in the context of clinical dental practice. Competencies 1-5 describe the skillset and tasks required by dentists to safely prescribe, whereas Competencies 6 and 7 describe the clinical environment and recommended resources to support dentists to prescribe safely and effectively.

CONCLUSIONS

The Prescribing Competencies Framework provides an overview of safe and effective prescribing. Prescribing is a process, and a separate skillset to clinical dentistry. The process involves information gathering, clinical assessment, effective communication and review of the patient. Access to timely and appropriate resources and relevant electronic sources of health information for clinicians are important to provide the support required for better informed prescribing decisions. The framework describes a patient-centered prescribing process, and ultimately prescribing should be a shared decision between the dentist and the patient.

CLINICAL SIGNIFICANCE

Safe and effective prescribing is an integral part of dentistry and dentists are the second largest prescriber group. However, dentists display high rates of inappropriate and unnecessary prescribing, and to minimise errors, the Prescribing Competencies Framework has been established. This article details how the Framework applies to clinical practice dentistry.

[Pruebas diagnósticas in vivo en alergia inmediata a penicilina: estudio piloto]

Background

The most commonly reported antibiotic allergy is penicillin. The false label of "allergy" to penicillin negatively affects the patient's quality of life and medical care.

Objective

To determine the frequency of allergy to penicillin and amoxicillin by in vivo exposure tests in patients with a history of immediate reaction to this class of medicinal products.

Methods

Observational, cross-sectional, descriptive and prolective study in patients between 12 and 60 years of age with a history of immediate reaction to penicillin and/or amoxicillin. Prick and intradermal skin tests were performed with benzylpenicilloyl polylysine (Pre-Pen), penicillin G and oral challenge test with amoxicillin. The frequency of positivity and negativity in these tests was calculated with a 95% CI. Results were analyzed in Epi info 7.2.5.0.

Results

In total 13 patients (10 women) were included, with a mean age of 39 years (SD 12.14). In 84.6% the last adverse drug reaction occurred 10 years ago and in all manifested with urticaria. The 38.4% confirmed penicillin allergy and the most frequent adverse reaction after in vivo tests was pruritus.

Conclusions

The clinical history alone is not sufficient, all patients with suspected penicillin allergy should be evaluated by in vivo exposure tests with major and minor determinants to corroborate or rule out allergy to this pharmacological class.

Penicillin allergy that persisted after 66 years: case report

The most common documented allergy is due to penicillin use, and penicillin allergy is often diagnosed early in childhood. However, fewer than 1% of the approximately 10% of the population with reported penicillin allergy have a true allergy. Antimicrobial stewardship programmes have employed pharmacist-led protocols to rechallenge patients with a documented history of penicillin allergy. There are published data to suggest that patients with a history of penicillin allergy can be successfully rechallenged and desensitised. We report a case of a 74-year-old woman with a documented childhood history of penicillin allergy who was rechallenged with amoxicillin/clavulanate (Augmentin) in the hospital during admission. She was given one trial dose of amoxicillin/clavulanate for the treatment of urinary tract infection to cover organisms detected in the urine culture. Amoxicillin/clavulanate was determined to be the most suitable antibiotic for empirical treatment. Given a documented history of penicillin allergy from over 60 years ago, the likelihood of reactivity was suspected to be low to none. The patient, however, developed an allergic reaction after the one-time oral amoxicillin/clavulanate 875/125 mg dose trial.

Update of the consensus document on the aetiology, diagnosis and treatment of acute otitis media and sinusitis

Update of the consensus on acute otitis media (AOM) (2012) and sinusitis (2013) following the introduction of pneumococcal vaccines in the immunization schedule, and related changes, such as epidemiological variation, colonization by of nonvaccine serotypes and emerging antimicrobial resistances. A majority of studies show that the introduction of the pneumococcal 13-valent conjugate vaccine has been followed by a reduction in the nasopharyngeal carriage of pneumococcus, with an increase in the proportion of drug-resistant nonvaccine serotypes. The diagnosis of AOM is still clinical, although more stringent criteria are proposed, which are based on the visualization of abnormalities in the tympanic membrane and the findings of pneumatic otoscopy performed by trained clinicians. The routine diagnosis of sinusitis is also clinical, and the use of imaging is restricted to the assessment of complications. Analgesia with acetaminophen or ibuprofen is the cornerstone of AOM management; watchful waiting or delayed antibiotic prescription may be suitable strategies in select patients. The first-line antibiotic drug in children with AOM and sinusitis and moderate to severe disease is still high-dose amoxicillin, or amoxicillin-clavulanic acid in select cases. Short-course regimens lasting 5-7 days are recommended for patients with uncomplicated disease, no risk factors and a mild presentation. In allergic patients, the selection of the antibiotic agent must be individualized based on severity and whether or not the allergy is IgE-mediated. In recurrent AOM, the choice between watchful waiting, antibiotic prophylaxis or surgery must be individualized based on the clinical characteristics of the patient.

The efficacy and safety of a shortened duration of antimicrobial therapy for group A Streptococcus bacteremia

OBJECTIVES

To determine if shorter courses of antibiotic therapy for group A Streptococcus (GAS) bacteremia are associated with excess mortality.

METHODS

In this retrospective study of consecutive cases of GAS bacteremia in tropical Australia, the duration of antibiotic therapy was correlated with 90-day all-cause mortality.

RESULTS

There were 286 episodes of GAS bacteremia; the patients' median (interquartile range) age was 60 (48-71) years and 169/286 (59.1%) patients identified as an Indigenous Australian. There were 227/286 (79.4%) patients with a significant comorbidity. The all-cause 90-day mortality was 16/286 (5.6%); however, 12/16 (81.3%) patients died while still receiving their initial course of antibiotics and only 7/16 (43.8%) deaths were directly attributable to the GAS infection. After excluding patients who died while taking their initial course of antibiotics and those in whom the duration of therapy was uncertain, there was no difference in 90-day mortality between patients receiving ≤5 days of intravenous antibiotics and those receiving longer courses (1/137 [0.7%] vs 3/107 [2.8%], P-value = 0.32) nor in patients receiving ≤10 days of total therapy and those receiving longer courses (1/67 [1.5%] vs 3/178 [1.7%], P-value = 1.0).

CONCLUSION

Even among patients with significant comorbidity, shorter antibiotic courses for GAS bacteremia are not associated with excess mortality.

CROSS-REACTIVITY TO ANTIBIOTICS: PROPOSITIONS FOR SELECTING ALTERNATIVES

OBJECTIVE

The aim: To analyze CR among antibacterials of different classes and to overcome some widespread misconceptions regarding CR between different classes of antibiotics.

PATIENTS AND METHODS

Materials and methods: The narrative review represents an assessment of the most pertinent literary sources published in English language, which dealt with the issues of cross-reactivity between individual antibiotics and different classes of these ones.

CONCLUSION

Conclusions: With a high probability of type I AR in a patient in the past, it is better to plan the treatment of patients together with an allergist / immunologist. If this probability is estimated to be low, the choice of a particular antibiotic may be based to some extent on CR data.

Carbapenemase producing Enterobacteriaceae: Environmental reservoirs as primary targets for control and prevention strategies

Carbapenemase-producing Enterobacteriaceae (CPE) have become one of the greatest public health challenges globally. In the past decade, antimicrobial resistance (AMR) was viewed as a clinical problem in many parts of the world; hence, the role and magnitude of the contribution of the environment were not well appreciated. This review article was done with online published articles extracted from different databases using search terms related to the work. Evidence has shown that there exists the presence of carbapenemase genes in the environment, consequently fuelling the dissemination with alarming consequences. CPE when acquired causes life-threatening infections in humans. The health and economic impact of these infections are numerous, including treatment failure due to limited therapeutic options which hamper the containment of infectious diseases, further contaminating the environment and worsening the public health challenge. It is a well-known fact that the rate of emergence of resistant genes has outpaced the production of new antimicrobial agents, so it is pertinent to institute effective environmental measures to combat the spread of AMR organisms before it will completely gain a foothold and take us back to 'the pre-antibiotic era'. Environmental sources and reservoirs of resistant genes should therefore be amongst the primary targets for the control and prevention of the spread of resistant genes in the environment. This calls for the effective implementation of the 'one health' strategy with stakeholders committed to the design and enforcement of environmental mitigation policies and guidelines.

Impact of Fungal Spores on Asthma Prevalence and Hospitalization

Despite making up a significant proportion of airborne allergens, the relationship between fungal spores and asthma is not fully explored. Only 80 taxa of fungi have so far been observed to exacerbate respiratory presentations, with Cladosporium spp., Aspergillus spp., Penicillium spp., and Alternaria spp. found to comprise the predominant allergenic airborne spores. Fungal spores have been found in indoor environments, such as hospitals and housing due to poor ventilation. Meanwhile, outdoor fungal spores exhibit greater diversity, and higher abundance and have been associated with hospitalizations from acute asthma presentations. In addition, fungal spores may be the underlying, and perhaps the “missing link”, factor influencing the heightened rate of asthma presentations during epidemic thunderstorm asthma events. To improve our knowledge gap on fungal spores, airborne allergen monitoring must be improved to include not only dominant allergenic fungi but also provide real-time data to accurately and quickly warn the general public. Such data will help prevent future asthma exacerbations and thus save lives. In this review, we examine the health risks of prominent allergenic fungal taxa, the factors influencing spore dispersal and distribution, and why improvements should be made to current sampling methods for public health and wellbeing.

β-lactam exposure outcome among patients with a documented allergy to penicillins post-implementation of a new electronic medical record system and alerting rules

BACKGROUND

Recent studies suggest that type I hypersensitivity cross-reactivity between β-lactam antibiotics is due to side chain similarity and not the common β-lactam ring. As a result, the prescriber-alerting rules of an electronic medical record (EMR) system were adjusted to only flag prescribers when prescribing penicillins or β-lactams with similar side chains (viz, cephalexin, cefadroxil, and cefoxitin) to patients with a documented allergy to penicillins. This study was conducted to assess and confirm the safety of the adjusted alerting rules; the primary outcome was the prevalence of anaphylaxis on β-lactam re-exposure.

METHODS

Retrospective chart review was conducted for patients who, under the reformed alerting rules, received a β-lactam antibiotic post-documentation of an allergy to penicillins in their EMR from April 2018 to July 2019 at a 268-bed community hospital. Given the volume of eligible patients, a 25% sample was randomly selected for review from initiation of the β-lactam antibiotic up to 30 days post-exposure to determine the prevalence of anaphylaxis.

RESULTS

Of the 325 charts reviewed, 300 patients (92.3%) received a β-lactam antibiotic with a different side chain than penicillins (not alerted on prescribing). Chart review of these 300 patients confirmed no reports of anaphylaxis secondary to β-lactam exposure (0%), and two patients developed non-anaphylactic delayed reactions (rash).

CONCLUSIONS

There were no reports of immediate life-threatening anaphylaxis under the reformed alerting rules, despite 25 patients (7.7%) receiving an alerted drug, such as piperacillin-tazobactam. The reformed alerting rules better reflect current literature and reduce the risk of prescriber-alerting fatigue without compromising patient safety. The occurrence of delayed reactions reinforced the need to monitor for these reactions on β-lactam antibiotic prescribing.

Antimicrobial stewardship in dental practice

BACKGROUND

Antibiotic resistance is a global public health problem that is responsible for increased patient morbidity and mortality and financial burden. Dental antibiotic prescribing contributes to approximately 10% of all antibiotic prescriptions, and an estimated 80% of that prescribing is deemed inappropriate. Dental antimicrobial stewardship (AMS) has an important role to play in international efforts to tackle antibiotic resistance. The aim of the authors was to comment on the implementation of AMS strategies in outpatient dental practices.

METHODS

The authors included previous studies regarding outpatient antibiotic stewardship, longitudinal studies quantifying dispensed dental antibiotic prescription use, and interventional studies aimed at implementing AMS interventions in dentistry.

RESULTS

Researchers in several studies conducted trials regarding the use of various interventions, mostly comprising a combination of audit, feedback, dissemination of guidelines, and educational components to improve dental prescribing.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

In regard to the establishment of an AMS strategy, aspects to be considered should include raising awareness about the risks of unnecessary use of antibiotics. Engaging and educating the entire dental team and patients, as well as collaborating with other specialized professionals, are important elements. Context-specific interventions with a methodical and measured approach are ideal.