What constitutes a “severe” allergic reaction? How does epinephrine actually work? Can you use an expired auto-injector in an emergency?
Allergic Living asked Dr. Phil Lieberman, clinical professor of medicine and pediatrics at the University of Tennessee’s College of Medicine (and father and grandfather to food-allergic children), for answers to nine food allergy questions you’ve been wondering about but haven’t had a chance to ask.
1. What are the typical hallmarks of severe allergic reaction?
Reactions that involve the respiratory tract system (upper and lower areas) and the cardiovascular system. For example, coughing, wheezing, shortness of breath, inability to breathe because of upper airway swelling, cardiac arrhythmias, fall in blood pressure with shock, and even a heart attack typify a severe allergic reaction.
2. What do the new food allergy guidelines produced by the National Institute of Health/National Institute of Allergy and Infectious Diseases say constitutes an anaphylactic reaction to food?
If any two of the following body organ systems (skin, GI tract, cardiovascular, airway or central nervous) are affected, this automatically requires the use of an auto-injector of epinephrine. If a known allergen is ingested and there is a single manifestation of any reaction in any of those bodily systems, this also automatically requires use epinephrine. For a deeper explanation, the National Institute of Allergy and Infectious Diseases has patient guidelines  that can be downloaded for free.
3. What is the best course of action in the event of an anaphylactic reaction?
Immediately inject epinephrine and then call 911. A second dose should be available and it should be administered in 10 minutes if there has been no improvement and/or if an emergency medical facility has not been reached. To prevent threatening falls in blood pressure, you can lie down and elevate your legs as well, if this posture does not make it difficult to breathe.
4. What exactly is epinephrine and how does it work in the body? What does it do to a severe reaction?
Epinephrine is a hormone the body makes itself: the “fight or flight” hormone. It is designed to increase blood flow to muscles, strengthen contractions of the heart and increase alertness. Its other name is adrenaline because it is manufactured in the adrenal gland.
5. Are there any side effects or risks of using an autoinjector of epinephrine?
In general, there are no severe side effects from the administration of epinephrine. Because it is the “fight or flight” hormone, it can make you jittery, raise your blood pressure and in some patients, cause tremors. In a healthy individual, this is uncomfortable but is not a threat. In some patients who have high blood pressure or heart disease, more severe side effects can occur. Still, in a case of anaphylaxis, the risk/benefit ratio favors the administration of the drug since anaphylaxis is a life-threatening condition.
Next page: “Is there a difference between different manufacturers of epinephrine?”
6. Is there a difference between different manufacturers of epinephrine?
There is no difference in the epinephrine contained in the automatic injectors that are available. The differences involved are differences in the device used to administer the epinephrine. For example, in the Twinject, two doses are supplied, but the second dose is not administered via an automatic injector but via a traditional syringe device. The generic is the same device as the Adrenaclick, which is an automatic epinephrine injector but it does not contain a sharps protector. Also the technique of administration is slightly different from that of the other automatic epinephrine injector, the EpiPen, which does contain a sharps guard to prevent an accidental needle stick. Because of the differences in these devices, make sure that you receive the same device that you were trained on. [Editor’s note: Since this article was written, the Auvi-Q (Allerject in Canada) auto-injector has also become available.]
7. How should auto-injector of epinephrine be stored? What if you live in a very hot or very cold climate year-round?
For information regarding the storage of the autoinjector, check the package insert. That said, you may find the advice given on the insert to be impractical. It is more important to keep the device with you even if it cannot be stored as described in the package insert. Therefore, in real life, the issue of keeping the injector with you trumps the storage suggestions supplied in the insert.
8. If you are having a severe allergic reaction and only have an expired auto-injector of epinephrine or one where the liquid is discolored, what should you?
First, when you pick up an auto-injector at the pharmacist, check the expiration date and write it down, as you should refill the injector before each expiration date. If, however, you have forgotten to do this, or find that you have an injector which is out of date, even one in which the liquid has turned slightly brown, it is safe to administer the drug. It will probably not have the same potency as would be found in the unexpired injector, but it will still have some effect. It is best to take advantage of that effect since the administration of an out-of-date epinephrine injector is not harmful.
9. How do we dispose of expired auto-injectors of epinephrine properly?
Injectors should be disposed of at a facility which has a “sharps disposal protocol.” Some pharmacies do have sharps disposal facilities, hospitals have such facilities, and physicians’ offices also have them.