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

The current standard of first-line emergency treatment of anaphylaxis is intramuscular (IM) epinephrine, mostly administered through epinephrine autoinjector (EAI) in the outpatient setting. However, undercarriage and underuse of EAIs are common, and delayed epinephrine use is associated with increased morbidity and mortality. Patients, caregivers, and healthcare professionals have expressed a strong desire for small, needle-free devices and products that would offer improved carriage, ease of use, and more convenient, less invasive routes of epinephrine administration. Novel mechanisms of epinephrine administration are under investigation to help address several recognized EAI limitations. This review explores innovative nasal and oral products under investigation for the outpatient emergency treatment of anaphylaxis.

Human studies of epinephrine administered through nasal epinephrine spray, a nasal powder spray, and a sublingual film have been conducted. Data from these studies indicate promising pharmacokinetic results comparable to those of the standard of outpatient emergency care (0.3-mg EAI) and syringe and needle IM epinephrine administration. Several products have shown maximum plasma concentration values higher than those of the 0.3-mg EAI and manual IM injection, although it remains unclear whether this has clinical relevancy in patient outcomes. Generally, these modalities show comparable time to maximum concentrations. Pharmacodynamic changes observed with these products are comparable to or more robust than those seen with EAI and manual IM injection.

Given comparable or superior pharmacokinetic and pharmacodynamic results and safety of innovative epinephrine therapies to those of current standards of care, US Food and Drug Administration approval of these products may help address numerous barriers that EAIs present. The ease of use and carriage and favorable safety profiles of needle-free treatments may make them an attractive alternative to patients and caregivers, potentially addressing injection fears, needle-based safety risks, and other reasons for lack of or delayed use.