Why Do Some Need More Than One Epinephrine Shot in an Allergic Reaction?

Published: July 24, 2017

Q: Why do some people need more than one dose of epinephrine in a bad allergic reaction, while for many others, one auto-injector dose turns off the reaction? Is there a way to tell that a second will be necessary?

Dr. Sicherer: Most anaphylactic reactions do not require more than one dose of epinephrine. When a second epinephrine dose is needed, it may be because symptoms have not adequately resolved following the first dose or they may have come back as a second wave after improvement.

Some factors that have been noted as a risk for needing a second dose include:
– having a diagnosis of asthma;
– having severe symptoms during the reaction;
– and experiencing a delay in getting the first dose of epinephrine.

Two important conclusions are: administer epinephrine promptly with an auto-injector and get to an emergency room for observation.

The reason for going to an emergency room is not because epinephrine was given (it is a very safe medication), but rather because there was a significant reaction. In some patients’ reactions, the symptoms can return.

Dr. Scott Sicherer is a practicing allergist, clinical researcher and professor of pediatrics. He is Director of the Jaffe Food Allergy Institute and Chief of Pediatric Allergy and Immunology at the Icahn School of Medicine at Mount Sinai in New York. He’s also the author of Food Allergies: A Complete Guide for Eating When Your Life Depends On It.

18 Things to Know About Food Allergy Reactions E-Book

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