Pharmacokinetic and pharmacodynamic evidence of adrenaline administered via auto-injector for anaphylactic reactions: A review of literature

10 practical priorities to prevent and manage serious allergic reactions: GA2LEN ANACare and EFA Anaphylaxis Manifesto

This Anaphylaxis Manifesto calls on communities to prioritise 10 practical actions to improve the lives of people at risk of serious allergic reactions. The Global Allergy and Asthma European Network and the European Federation of Allergy and Airways Diseases Patients' Associations (EFA) compiled patient-centric priorities. We used qualitative consensus methods, research evidence and feedback from over 200 patient groups, stakeholder organisations and healthcare professionals. We encourage healthcare, education and food organisations to collaborate with people at risk of serious allergic reactions to tackle safety, anxiety and financial burdens for individuals and societies. Key priorities for prevention include awareness-raising campaigns for the public and professionals, school and workplace initiatives and mandatory precautionary allergen labels on food. Priorities for improving immediate and long-term management include educating healthcare professionals, patients and schools about when and how to use adrenaline, funding two approved adrenaline devices for everyone at risk, and facilitating access to allergy specialists. Integrated care pathways should include clinical and non-clinical management options such as individualised risk assessment and quality of life assessment, self-management plans, dietetic and psychosocial support and peer support. Organisations around the world are committing to work together towards these priorities.

Adrenaline auto injectors pharmacokinetic/pharmacodynamic studies and potential consequences for clinical practice

BACKGROUND

Anaphylaxis is a sudden multisystem allergic reaction which may result in a fatal outcome if not treated promptly. Guidelines worldwide suggest intramuscular adrenaline as the first-line treatment for anaphylaxis outside a perioperative reaction. Adrenaline autoinjectors (AAIs) are widely used self-administrable devices, especially in community settings. Different commercial AAIs have been authorized to be marketed in Europe. For an AAI to be efficacious, a rapid adrenaline delivery in patients, including those who are overweight or obese, resulting in an optimal cardiovascular (CV) response, is a key feature. AAIs are designed to achieve this requirement, which is reflected in their differing functional properties such as primary container selection, drug delivery mechanism (cartridge-or syringe-based), needle length, needle gauge, and adrenaline dose (150 μg, 300 μg, or 500 μg). However, the differences in functional properties across these devices may play a critical role in achieving these requirements as well as the differences in ergonomics in the handling of these devices.

THE PURPOSE OF THIS REVIEW

Considering the dynamic pharmacokinetic/pharmacodynamic (PK/PD) profiles of different AAIs marketed in Europe and their effect on adrenaline delivery, the expert panel, also serving as author for this paper have carried out a detailed analysis of the PK/PD profiles of four AAIs, namely, Anapen, Emerade, EpiPen, and Jext, to delineate the adrenaline delivery and their subsequent physiological effects on the backdrop of device characteristics, dose strength, and the skin-to-muscle distances of the participants.

Epinephrine autoinjectors: individualizing device and dosage to optimize anaphylaxis management in the community setting

Background: Anaphylaxis is the most severe manifestation of a systemic allergic reaction, and, in the community setting, the immediate administration of an epinephrine autoinjector (EAI) can be life-saving. Physicians are tasked with selecting the most appropriate EAI for each individual and counseling patients and/or their caregivers to maximize the likelihood of successful deployment of the EAI. Objective: To offer an evidence-based expert clinical perspective on how physicians might best tailor EAI selection to their patients with anaphylaxis. Methods: A group of eight adult and pediatric allergists with expertise in anaphylaxis management reviewed and assessed the published data and guidelines on anaphylaxis management and EAI device selection. Results: Personalized EAI selection is influenced by intrinsic individual factors, extrinsic factors such as the properties of the individual EAI (e.g., dose, needle length, overall design) as well as cost and coverage. The number and the variety of EAIs available have expanded in most jurisdictions in recent years, which provide a greater diversity of options to meet the characteristics and needs of patients with anaphylaxis. Conclusion: There currently are no EAIs with customizable dose and needle length. Although precise personalization of each patient's EAI remains an optimistic future aspiration, careful consideration of all variables when prescribing EAIs can support optimal management of anaphylaxis.

International recommendations on epinephrine auto-injector doses often differ from standard weight-based guidance: a review and clinical proposals

BACKGROUND

In anaphylaxis, the dosing of injectable epinephrine in medical settings has been arbitrarily recommended to be 0.01 mg/kg of body weight. For ethical reasons, there have been no dose-response studies or double-blind studies performed on patients with active anaphylaxis. Intramuscular delivery of epinephrine has been the standard. Auto-injectors for use in the treatment of anaphylaxis are available in four strengths (0.1, 0.15, 0.3, and 0.5 mg). However, in many countries, only the 0.15 and 0.3 mg strengths are available. Consequently, many adult, heavy patients are prescribed the 0.3 mg dose, which may result in only one-fifth to one-third of the recommended weight-based dose being administered in heavy patients experiencing anaphylaxis. Underdosing may have therefore contributed to mortality in anaphylaxis.

OBJECTIVE

To review the doses of epinephrine recommended for the treatment of anaphylaxis in the community, and assess whether recommendations should be made to increase dosing for heavy adult patients in hopes of avoiding future deaths from anaphylaxis.

METHODS

We reviewed multiple national and international recommendations for the dosing of epinephrine. We also reviewed the literature on adverse drug reactions from epinephrine, lethal doses of epinephrine, and epinephrine dose-finding studies.

RESULTS

The majority of national and regional professional societies and authorities recommend epinephrine delivered by auto-injectors at doses far lower than the generally accepted therapeutic dose of 0.01 mg/kg body weight. Furthermore, we found that the recommendations vary even within regions themselves.

CONCLUSIONS

We suggest prescribing more appropriate doses of epinephrine auto-injectors based on weight-based recommendations. There may be some exceptions, such as for patients with heart disease. We hypothesize that these recommendations will lead to improved outcomes of anaphylaxis.

Multicenter real-world experience with epinephrine 0.5 mg dosing for anaphylaxis with allergen immunotherapy

Aim: To determine the safety and efficacy of 0.5 mg intramuscular (IM) epinephrine for the treatment of subcutaneous allergen immunotherapy induced anaphylaxis. Patients & methods: Retrospective chart review of patients who received 0.5 mg of IM epinephrine for treatment of anaphylaxis from subcutaneous allergen immunotherapy at two outpatient allergy and immunology practices. Results: Thirty-eight patients received 0.5 mg IM epinephrine. Eleven patients (29%) required a second dose, and two patients (5%) required a third dose of IM epinephrine. Sixteen patients (42%) were transferred to the emergency department with ongoing symptoms. All had eventual resolution of anaphylaxis. There were no adverse reactions or fatalities. Conclusion: IM epinephrine at a dose of 0.5 mg is safe and effective for treatment of anaphylaxis from subcutaneous allergen immunotherapy.

Does COVID-19 Vaccination Warrant the Classical Principle "ofelein i mi vlaptin"?

The current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic warrants an imperative necessity for effective and safe vaccination, to restrain Coronavirus disease 2019 (COVID-19) including transmissibility, morbidity, and mortality. In this regard, intensive medical and biological research leading to the development of an arsenal of vaccines, albeit incomplete preconditioned evaluation, due to emergency. The subsequent scientific gap raises some concerns in the medical community and the general public. More specifically, the accelerated vaccine development downgraded the value of necessary pre-clinical studies to elicit medium- and long-term beneficial or harmful consequences. Previous experience and pathophysiological background of coronaviruses' infections and vaccine technologies, combined with the global vaccines' application, underlined the obligation of a cautious and qualitative approach, to illuminate potential vaccination-related adverse events. Moreover, the high SARS-CoV-2 mutation potential and the already aggregated genetical alterations provoke a rational vagueness and uncertainty concerning vaccines' efficacy against dominant strains and the respective clinical immunity. This review critically summarizes existing evidence and queries regarding SARS-CoV-2 vaccines, to motivate scientists' and clinicians' interest for an optimal, individualized, and holistic management of this unprecedented pandemic.

The pharmacokinetics of epinephrine/adrenaline autoinjectors

Background

For a century, epinephrine has been the drug of choice for acute treatment of systemic allergic reactions/anaphylaxis. For 40 years, autoinjectors have been used for the treatment of anaphylaxis. Over the last 20 years, intramuscular epinephrine injected into the thigh has been recommended for optimal effect.

Objective

To review the literature on pharmacokinetics of epinephrine autoinjectors.

Results

Six studies assessing epinephrine autoinjector pharmacokinetics were identified. The studies, all on healthy volunteers, were completed by Simons, Edwards, Duvauchelle, Worm and Turner over the span of 2 decades. Simons et al. published two small studies that suggested that intramuscular injection was superior to subcutaneous injection. These findings were partially supported by Duvauchelle. Duvauchelle showed a proportional increase in C_max and AUC_0-20 when increasing the dose from 0.3 to 0.5 mg epinephrine intramuscularly. Turner confirmed these findings. Simons, Edwards and Duvauchelle documented the impact of epinephrine on heart rate and blood pressure. Turner confirmed a dose-dependent increase in heart rate, cardiac output and stroke volume. Based on limited data, confirmed intramuscular injections appeared to lead to faster C_max. Two discernable C_max’s were identified in most of the studies. We identified similarities and discrepancies in a number of variables in the aforementioned studies.

Conclusions

Intramuscular injection with higher doses of epinephrine appears to lead to a higher C_max. There is a dose dependent increase in plasma concentration and AUC_0-20. Most investigators found two C_max’s with T_max 5–10 min and 30–50 min, respectively. There is a need for conclusive trials to evaluate the differences between intramuscular and subcutaneous injections with the epinephrine delivery site confirmed with ultrasound.