A new prescription for an EpiPen autoinjector is filled for JC, a 10 year-old male (weight 40kg).  When his mother comes to pick-up his new medication, she says that JC recently had to go to the emergency room for an anaphylactic reaction to a bee sting.  She says that she has never used an EpiPen before and would like the pharmacist to show her how it works.

Which of the following is an appropriate counseling point to give to JC’s mother about using an EpiPen during an episode of anaphylaxis?

A. Give a first-generation antihistamine like Benadryl before using the EpiPen

B. Inject the Epipen into the outer mid-thigh (anterolateral thigh)

C. Press the blue end of the EpiPen into the thigh to deliver the medication

D. A maximum of one dose of epinephrine should be administered

Answer with rationale:

Anaphylaxis is a type of acute life threatening allergic reaction involving the skin and/or mucosal tissue further characterized by respiratory compromise, hypotension, and/or severe gastrointestinal symptoms.  Epinephrine is the mainstay treatment of anaphylaxis.  It works on α, β1, and β2 receptors to increase blood pressure, increase cardiac output, and reverse bronchoconstriction and prevent the release of inflammatory mediators from mast cells, respectively.  Epinephrine comes in various forms: autoinjectors, nasal sprays, prefilled syringes, and solution vials.  The most common form of epinephrine used for the outpatient treatment of anaphylaxis, is the EpiPen autoinjector due to it not requiring dose measurements and ability to be self-administered. There are two commercially available doses which are the 0.3mg dose (EpiPen) for patients weighing 30kg or more or 0.15mg dose (EpiPen Jr.) for patients weighing 15-30kg. 

Answer A is incorrect.  Epinephrine is the first-line treatment for anaphylaxis because it is the only medication that can reverse the life-threatening symptoms of anaphylaxis and prevent death.  It should be administered at the first sign of anaphylaxis and should not be delayed.  While adjunctive therapies like H1 receptor antagonists, H2 receptor antagonists, glucocorticoids, and bronchodilators can be used as adjunctive therapies to treat the symptoms of anaphylaxis they should never be used before or in place of epinephrine.

Answer B is correct.  The EpiPen autoinjector delivers epinephrine intramuscularly and should be injected into the anterolateral thigh (i.e., the outer mid-thigh).  It can be injected through clothing.

Answer C is incorrect.  The EpiPen autoinjector has two colored ends: the orange end and the blue end.  The blue end is the safety release which must be pulled off before administering the dose.  The orange end contains the needle and is the end that is pressed against the skin to administer the dose.  The phrase “blue to the sky, orange to the thigh” may be helpful to remember this.

Answer D is incorrect.  EpiPen autoinjectors contain 1 dose of epinephrine per pen and each box contains two pens.  Multiple doses of epinephrine may be needed to reverse anaphylaxis.  Doses may be repeated every 5-15 minutes as needed. More than two sequential doses of epinephrine should only be administered under direct medical supervision. Even after administration of epinephrine, the patient should still go to the nearest emergency room to be monitored and receive additional treatment.

Brands/generics covered:

EpiPen (epinephrine), Benadryl (diphenhydramine)

NAPLEX content domains covered:

2.A.1

Domain 2 Medication Use Process- A. Prescriptions and Medication Order Interpretation 1. Drug Names and Therapeutic Classes

2.A.2

Domain 2 Medication Use Process- A. Prescriptions and Medication Order Interpretation 2. Indications, Usage, and Dosing Regimens

3.E.2

Domain 3 Person-Centered Assessment and Treatment Planning- E. Patient education 2. Medication use, storage, and disposal