Epinephrine Autoinjectors: how to use them correctly.

Epinephrine Auto-injectors

Lead author: Rhonda Wienkes, RPh.

Background

Anaphylaxis is a severe, life threatening reaction that may occur in response to a food, insect bite, drug, or other allergen. The most common presentation of an anaphylactic reaction involves respiratory difficulty due to swelling or asthma; or hypotension, which may present as fainting or loss of consciousness. Administration of intramuscular epinephrine, or adrenaline, as soon as possible after a reaction has been shown to produce positive outcomes. For this reason, an epinephrine auto-injector is available for high-risk patients to carry around with them at all times. Unfortunately, these high-risk patients either do not have a prescription for an epinephrine auto-injector or do not know how to properly administer the drug.1

Who should carry an epinephrine auto-injector?

Any patient who has experienced a severe systemic allergic reaction and has the potential of re-encountering the trigger should carry an epinephrine auto-injector.2

What is the appropriate dose of epinephrine for anaphylaxis?

For adult patients, the usual dose of epinephrine is 0.3 mg administered intramuscularly. The usual dose for infants and children is 0.01 mg/kg.2 The EpiPen and EpiPen Jr are the only available epinephrine auto-injectors. The EpiPen delivers 0.3 mg per dose and the EpiPen Jr delivers 0.15 mg per dose, which is appropriate for a child weighing around 15 kilograms. A physician has the option of giving a child weighing over 15 kilograms either the 0.3 mg or the 0.15 mg dose.2

The EpiPen and EpiPen Jr are both available in one auto-injector packages as well as two-packs that include a reusable trainer device.2 This could be used during counseling and also at home to train all members of the family.

Proper administration techniques

Epinephrine auto-injectors should be administered perpendicular to the outer thigh muscle. The gray activation cap must first be removed, and the device pointed at the thigh with the black tip down. After delivering a dose, the auto-injector should be held in place for several seconds, and then the injection area of the thigh should be massaged to help the distribution of the epinephrine. Specific directions and pictures are dispensed with every product.2

The auto-injectors should be kept in their original plastic carrying tube that provides protection from UV light. They also should be stored away from extreme heat or cold and periodically examined for color changes or the presence of solid particles.2

Counseling tips

Help patients by making sure that all epinephrine auto-injectors that are dispensed have at least a one year expiration. Remind patients to request a refill when the drug reaches its expiration date or if the solution changes color. The distributor offers a free reminder service to notify patients one month before their Epipen expires. Enrollment forms for this service are included with the package insert or can be found online at www.epipen.com. Pharmacists could also consider providing this service for their patients.

Assure patients that as long as the needle is visible after administration, the dose was properly delivered. About 90% of the liquid will remain in the auto-injector after use and cannot be reused.2

Encourage the patient to carry the auto-injector, especially when there is a risk of encountering his or her specific allergen. Advise patients who injected the epinephrine to proceed quickly to a hospital for further care.3

It is probably a good idea to counsel all refills of epinephrine auto-injectors since they are rarely used and technique could be easily forgotten in an emergency. All family and caregivers should also be educated on proper administration.3

References

McLean-Tooke AP, Bethune CA, Fay AC, Spickett GP. Adrenaline in the treatment of anaphylaxis: what is the evidence? BMJ 2003;327:1332-5.
Product information for EpiPen. DEY. Napa, CA 94558. December 2000.
Hayman GR, Bansal JA, Bansal AS. Knowledge about using auto-injectable adrenaline: review of patients' case notes and interviews with general practitioners. BMJ 2003;327:1328.
March 2004