Epinephrine in Anaphylaxis: Too Little, Too Late

Jay Adam Lieberman; Julie Wang


Curr Opin Allergy Clin Immunol. 2020;20(5):452-458. 

In This Article

Data Supporting Early Administration of Epinephrine

The more common way that the role of epinephrine in anaphylaxis treatment is assessed is by examining large databases of anaphylaxis or smaller cohorts of severe or fatal anaphylaxis. From the early case fatality studies by Sampson and Pumphrey, there seems to be a theme that there was a delay in administration of epinephrine in fatal anaphylactic reactions.[16,17] Table 1 highlights findings from more recent selected cohort/database studies of anaphylaxis in which epinephrine administration was reportedly associated with outcomes.

It is important to understand, however, that reporting a low incidence of use or delayed administration of epinephrine in a cohort of fatal cases does not infer causality, especially when we do not know the percentage of patients with milder reactions who got epinephrine and when.

As described above, many of the fatal case series concluded that delay in administration of epinephrine was a risk for fatal anaphylaxis.[16–18,22] However, the key flaw in that conclusion is that we do not know the outcome had they gotten epinephrine earlier and we do not have comparator groups in most studies who survived where times of epinephrine administration relative to symptom onset were well documented.

From the studies examining nonfatal outcomes, there are signals to suggest that early administration of epinephrine can decrease hospitalizations or possibly severity of reactions (based on surrogate markers).[19–21] Thus, there are some data to argue that early epinephrine can at least decrease morbidity if not mortality from anaphylaxis.