Who Needs Epinephrine? Anaphylaxis, Autoinjectors, and Parachutes

International guidelines stipulate that intramuscular (IM) epinephrine (adrenaline) is the first-line treatment for anaphylaxis, with an established good safety profile. The availability of epinephrine autoinjectors (EAI) has greatly facilitated the lay administration of IM epinephrine in community settings. However, key areas of uncertainty remain around epinephrine usage. These include variations in prescribing EAI, what symptoms should prompt epinephrine administration, whether emergency medical services (EMS) need to be contacted after administration, and whether epinephrine administered via EAI reduces mortality from anaphylaxis or improves quality of life measures. We provide a balanced commentary on these issues. There is increasing recognition that a poor response to epinephrine, particularly after 2 doses, is a useful marker of severity and the need for urgent escalation. It is likely that patients who respond to a single epinephrine dose do not require EMS activation or emergency department transfer, but data are needed to demonstrate the safety of this approach. Lastly, patients at risk of anaphylaxis must be counseled against over-reliance on EAI alone. (c) 2023 The Authors. Published by Elsevier Inc. on behalf of the American Academy of Allergy, Asthma & Immunology. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). (J Allergy Clin Immunol Pract 2023;11:1036-46)

Automated summary

International guidelines recommend intramuscular epinephrine as the first-line treatment for anaphylaxis, and the availability of epinephrine autoinjectors has facilitated its administration in community settings. However, there are uncertainties regarding the usage of epinephrine, such as variations in prescribing autoinjectors, when to administer epinephrine, the need to contact emergency medical services, and the impact of epinephrine on mortality and quality of life. A poor response to epinephrine after 2 doses may indicate severity and the need for urgent escalation, but more research is needed to confirm the safety of not activating emergency medical services in patients who respond to a single dose. Patients at risk of anaphylaxis should be cautioned against relying solely on autoinjectors.