Innovations in the treatment of anaphylaxis: A review of recent data

A health economic analysis of noninjectable epinephrine compared with intramuscular epinephrine

BACKGROUND

Noninjectable epinephrine to treat allergic reactions addresses an unmet need. Intranasal epinephrine is approved and a sublingual form is under development. Inhaled epinephrine is poorly studied for anaphylaxis. These forms have unknown cost-effectiveness.

OBJECTIVE

To evaluate cost-effectiveness of commercially available noninjectable epinephrine compared with intramuscular epinephrine for treatment of anaphylaxis.

METHODS

Markov cohort analyses evaluated the cost-effectiveness of noninjectable epinephrine forms. The base-case assumed exaggerated anaphylaxis fatality rates (50-fold increase) for using inhaled epinephrine given low certainty evidence in anaphylaxis and deliberately reduced fatality risk for nasal or sublingual forms (10-fold reduction) theorizing higher adherence and early use during an allergic reaction.

RESULTS

In the base-case scenario, assuming a 10-fold decreased risk in peanut allergy fatality associated with intranasal or sublingual epinephrine treatment for a severe allergic reaction (net monetary benefit [NMB], $2,189,134) vs intramuscular epinephrine use (NMB, $2,189,114), intranasal or sublingual epinephrine was the most cost-effective option (incremental cost-effectiveness ratio [ICER], $83,748/quality-adjusted life-year [QALY]), but only at a marginal annual cost of $4. Intramuscular epinephrine was cost-effective (ICER, $17,900/QALY) vs inhaled epinephrine (NMB, $2,183,531), although inhaled epinephrine reached cost-effectiveness (willingness to pay [$100,000/QALY]) if associated fatality risk fell below 2.5-fold. Substituting a single noninjectable form of epinephrine for a second injectable device (in patients prescribed 2 autoinjectors already) would be cost-effective; however, adding a supplemental noninjectable device was not cost-effective, even assuming a 10-fold risk reduction with multiple device carriage (ICER, $858,462).

CONCLUSION

Noninjectable routes of epinephrine can be cost-effective options provided fatality risk is not significantly elevated. Carriage of redundant epinephrine autoinjectors with noninjectable forms is not cost-effective if associated with excess cost of redundant device packs.

Benefits of Epinephrine for Anaphylaxis Outweigh Potential Harm-A Safety Review

Anaphylaxis is a potentially life-threatening allergic reaction that can progress quickly, and although fatal anaphylaxis is very rare, treatment should be given as soon as possible. The recommended first-line treatment for anaphylaxis is intramuscular (IM) epinephrine. Yet epinephrine for anaphylaxis is underused, which can have deleterious, or even tragic, consequences. Although fear of self-injection substantially affects adherence, hesitancy to use epinephrine for anaphylaxis may be linked to the common unsubstantiated perception that epinephrine is dangerous. Therefore, the objective of this narrative review is to describe the safety of epinephrine when administered for the treatment of anaphylaxis. Cardiovascular adverse events (AEs) are the greatest safety concern with epinephrine because of its known effects on cardiac output and vasoconstriction. Cardiovascular events and overdose are significantly more likely to occur with accidental intravenous bolus administration than IM administration. Although serious AEs have been reported with IM epinephrine, and there are potential risk factors for cardiovascular AEs for some patients, there are no absolute contraindications for its use in a life-threatening situation. Appropriately dosed and administered epinephrine should engender no fear of use for anaphylaxis. The potential harm of delaying or withholding epinephrine treatment for anaphylaxis far outweighs the potential risk of AEs.

Updates in Food Anaphylaxis Management

The management of food allergy has evolved over the past several years with regulatory approval of food allergy therapeutics as well as the common practice of oral immunotherapy. Whether a patient or family chooses one of these therapies or avoidance, they are still considered at risk of reaction, and thus clinicians still need to stay up to date with the latest advancements in the management of anaphylaxis in patients with food allergy. This review will highlight some of these updates, starting with the definition, diagnosis, and classifications of anaphylaxis. It will then review the latest updates in the management of food anaphylaxis in the community. Finally, the review will discuss the latest in epinephrine including recommendations on epinephrine dosing and novel routes of epinephrine administration.

Pearls for practice from the 2023 joint task force anaphylaxis practice parameter

PURPOSE OF REVIEW

To share important highlights on the management of anaphylaxis from the latest 2023 practice parameter.

RECENT FINDINGS

The 2023 Allergy Immunology Joint Task Force on Practice Parameters (JTFPP) anaphylaxis practice parameter provides updated anaphylaxis guidance. Criteria for the diagnosis of anaphylaxis are reviewed. The parameter highlights that while anaphylaxis is not more severe in younger children, age-specific symptoms can vary. Activation of emergency medical services may not be required in patients who experience prompt resolution of symptoms following epinephrine use and caregivers are comfortable with observation. For children weighing <15 kg, the anaphylaxis parameter suggests the clinician may prescribe either the 0.1 mg or the 0.15 mg epinephrine autoinjector, with the 0.3 mg autoinjector prescribed for those weighing 25 kg or greater. In patients with heart disease, discontinuing or changing beta blockers and/or angiotensin converting enzyme inhibitors may pose a larger risk for worsened cardiovascular disease compared with risk for severe anaphylaxis with medication continuation. Furthermore, in patients with a history of perioperative anaphylaxis, shared decision-making based on diagnostic testing and clinical history is recommended prior to repeat anesthesia use. Beyond the recent parameter update, novel contemporary therapies can decrease risk of community anaphylaxis.

SUMMARY

The 2023 JTFPP Anaphylaxis Guidelines offer up-to-date guidance for the diagnosis and management of anaphylaxis in infants, children, and adults.

Alternatives to Injectable Adrenaline for Treating Anaphylaxis

Adrenaline is the first line treatment for anaphylaxis and adrenaline auto-injectors (AAI) allow reliable, safe and ergonomic administration in the community. However, AAIs have significant limitations and adrenaline is often not used in anaphylaxis. Innovations to administer adrenaline via alternative routes may potentially improve usage rates and treatment effectiveness. Here, we describe the known limitations and barriers to AAI use in anaphylaxis. We then summarise current data for adrenaline devices which use alternative routes of administration for treating anaphylaxis. Several novel devices are in development, which deliver adrenaline via nasal, sublingual or transcutaneous routes. Pharmacokinetic, pharmacodynamic and safety studies have compared these treatments with AAI or intramuscular adrenaline via needle and syringe. The first non-injectable adrenaline delivery device for emergency treatment of anaphylaxis was approved in Europe and the United States. Neffy, an adrenaline nasal spray, is licensed for use in adult and paediatric patients who weigh at least 30 kg. In the near future, multiple alternatives to injectable adrenaline may be available for managing anaphylaxis, overcoming some, but not all of the limitations of AAIs.

Pharmacokinetic and Pharmacodynamic Profile of Epinephrine Nasal Spray Versus Intramuscular Epinephrine Autoinjector in Healthy Adults

BACKGROUND

Standard of care for anaphylaxis treatment is intramuscular (IM) epinephrine. An epinephrine nasal spray (ENS) is under development as an alternative form of administration.

OBJECTIVE

To compare the pharmacokinetic and pharmacodynamic (PD) profile of 13.2 mg ENS with 0.3 mg IM epinephrine autoinjector.

METHODS

Data from 4 open-label phase 1 crossover studies conducted in healthy adults were pooled to determine the pharmacokinetic and PD profile of a single 13.2 mg ENS dose delivered by 2 consecutive sprays of 6.6 mg each in opposite (n = 224 doses) or the same nostril (n = 75 doses) compared with the 0.3 mg IM autoinjector (n = 215 doses). Each participant served as their own control. Blood samples and vital signs were collected predose and at multiple intervals from 0 to 360 minutes postdose.

RESULTS

ENS rapidly increased the plasma epinephrine concentration, with levels that were overall greater than IM autoinjector. Median (range) time to maximum plasma epinephrine concentration with ENS opposite nostrils, ENS same nostril, and IM autoinjector was 25.1 (1.3-362.1), 20.1 (3.0-120.2), and 20.0 (1.0-121.3) minutes, respectively. The area under the plasma concentration-time curve for 0 to 360 minutes was significantly higher with ENS than with the IM autoinjector (geometric mean ratio [90% CI], 155% [140%-172%] with ENS opposite nostrils, 159% [138%-182%] with ENS same nostril). The PD effects on heart rate and blood pressure were similar in pattern and magnitude among all 3 treatment groups.

CONCLUSIONS

ENS rapidly achieved plasma epinephrine levels greater and more sustained than the IM autoinjector and with a similar PD effect.

To the ER? Can Patients Treat Their Anaphylaxis at Home?

PURPOSE OF REVIEW

To discuss if all patients who use self-injectable epinephrine outside the hospital setting require immediate emergency care.

RECENT FINDINGS

Prior to 2023, anaphylaxis management guidance universally recommended that patients who use self-injectable epinephrine outside of the hospital or clinic setting immediately activate emergency medical services and seek further care. Additional food-induced anaphylaxis management recommendations specified that all patients always carry 2 auto-injector devices and give a second dose of epinephrine if there was not immediate response within 5 min of injection. Patients presenting for emergency care after epinephrine are often observed for up to 4-6 h afterwards, even when completely asymptomatic. These management steps have lacked evidence for improving outcomes, and universal implementation of these approaches is not cost-effective as guidance for food allergic patients. Epinephrine pharmacokinetics and pharmacodynamics suggest that peak physiologic response is more likely to occur closer to 15 min than before 5 min, that few patients require a second dose of epinephrine as most stabilize within 15 min of use, that 60 min of observation after a patient stabilizes after epinephrine use may be adequate as patients infrequently have further sequelae, and that not everyone needs to carry 2 epinephrine auto-injectors on their person at all times. The most recent anaphylaxis practice parameter promotes a contextualized approach to these management questions, outlining the option for watchful waiting to gauge response to epinephrine before seeking emergency care, which has been proven as a more cost-effective management strategy. The recent updated anaphylaxis care guidelines support the evolution of anaphylaxis care, in that universal, immediate activation of emergency services is not required for using self-injectable epinephrine outside the hospital setting.

A Media Advocacy Toolkit for the Allergist-Immunologist

For clinicians involved in improving healthcare for patients with allergic and immunologic conditions, advocacy on a broader level through public outreach is key to advancing value-based care. In this article, we provide a toolkit of strategies and resources that can be used to raise public awareness of important issues through various mediums, including podcasts and social media, newspapers, testimonies, presentations, and interviews. A simple approach to effective media interactions is described using the acronym "RATIO," which stands for Research, Audience, Targeted topic, Interview rephrasing, and Optimism. The acronym also reminds the person who is presenting information that only a fraction of what is discussed will be recalled, and an even smaller proportion will be implemented. Key points should be made early. Examples of key talking points are provided for selected topics, including food allergy, anaphylaxis, asthma, rhinitis, and broader healthcare advocacy.

Evidence-based use of epinephrine in anaphylaxis

PURPOSE OF REVIEW

Epinephrine is the first line treatment for anaphylaxis, however, there are limited data to support this. This review examines data surrounding evidence for the use of epinephrine in anaphylaxis, data on prescription for and use of epinephrine autoinjectors, and data examining newer routes of delivery of epinephrine; with a focus on recent publications over the past few years.

RECENT FINDINGS

With recent epidemiologic studies of anaphylaxis and new forms of epinephrine being studied, new data on the effects of epinephrine are aiding in the understanding of epinephrine's effects and the shortcomings of epinephrine both in its effect and utility in the real world.

SUMMARY

Epinephrine is still considered the first line therapy for anaphylaxis, and we are starting to have a better understanding of its effects in both healthy patients and those with anaphylaxis.

Epinephrine autoinjectors for individuals with food allergy: Who, how many, and when to use

Background

Anaphylaxis is a serious allergic reaction that is effectively treated with epinephrine. Epinephrine autoinjectors are devices that contain fixed doses of medication that can be carried by patients at risk for anaphylaxis so that ready access to first line medication is available outside the medical setting.

Methods

This review will discuss recent studies evaluating patient characteristics to consider when prescribing epinephrine autoinjectors.

Results

Decisions regarding who should be prescribed epinephrine autoinjectors will depend on the type of allergy, as well as co-morbidities and other risk factors that can increase a patient's risk for poor outcomes.

Conclusion

Shared decision-making is essential when developing guidance regarding post-epinephrine management. Regular education during routine follow-up visits can reinforce knowledge and skills for managing food allergy reactions.

Anaphylaxis: Definition and criteria

Anaphylaxis is a systemic allergic reaction that may be severe and life-threatening. With more than a dozen anaphylaxis definitions proposed over the past several decades and several diagnostic criteria in circulation, there is a need for a multinational consensus definition to simplify management across specialties. Anaphylaxis diagnostic criteria are more alike than they are different, and approaches of the National Institute of Allergy and Infectious Disease, World Allergy Organization, and Brighton Collaborative help to add granularity and perspective to patient management. Anaphylaxis occurs across a spectrum of severity within populations, although, among individual patients, there is some evidence to suggest more consistency for an individual allergen. Still, severity is influenced by a number of factors that demonstrate variability: factors that relate to allergen triggers, patient characteristics, and treatments received. Severity of anaphylaxis impacts management, and recent guidelines provide approaches that consider individual factors to inform both strong and conditional recommendations. Conditional recommendations serve as navigational signals for shared decision-making when patient expertise is leveraged to inform individual preferences and values together with clinician expertise in anaphylaxis management to provide patient care bespoke to each patient. As novel approaches to both prevention and treatment of anaphylaxis emerge, an understanding of the significance of strong and conditional recommendations becomes critical to providing individualized and appropriate care for patients at risk for anaphylaxis.