Epinephrine for Anaphylaxis: What Pharmacists Should Know

SEPTEMBER 13, 2016
Epinephrine has been a hot topic in the news lately because of the EpiPen’s increasing cost.
 
The first epinephrine auto-injector was invented in the mid-1970s and approved in 1987. Yet, since Mylan purchased EpiPen in 2007, the product has increased in price by more than 400%, which has sparked public outrage and inquiries from Congress.
 
Despite EpiPen having an 85% market share, there are still several other epinephrine formulations commercially available, with future generics to come. Here are several key therapeutics areas for epinephrine every pharmacist should know:
 
Indication
Epinephrine is indicated for the emergency treatment of allergic reactions (Type I), including anaphylaxis, which is defined as an acute, life-threatening allergic reaction. It can be triggered by insect stings or bites, foods, drugs, and other allergens, or it can be idiopathic or exercise-induced. Signs and symptoms include trouble breathing, hives or swelling, tightness of the throat, nausea, vomiting, abdominal pain, dizziness, and rapid heartbeat.
 
The estimated prevalence of anaphylaxis is 1% to 2%, with many studies suggesting increasing numbers. Food allergies in children alone account for more than 200,000 emergency department visits every year and an economic burden of nearly $25 billion per year.
 
Epinephrine, either as a prefilled auto-injector or drawn with a syringe, is the treatment of choice for anaphylaxis. It’s recommended to be given at the first sign of anaphylaxis, regardless of cause.
 
Mechanism of Action
Epinephrine is a nonselective alpha- and beta-adrenergic receptor agonist. Through its action on alpha-adrenergic receptors, it reduces vasodilation and increases vascular permeability that occurs during anaphylaxis. Its action on beta-adrenergic receptors results in bronchial smooth muscle relaxation, which helps alleviate bronchospasm, wheezing, and dyspnea that may occur during anaphylaxis.
 
Epinephrine also reduces pruritus, urticaria, and angioedema and may relieve gastrointestinal and genitourinary symptoms associated with anaphylaxis because of its relaxer effects on the smooth muscle of the stomach, intestine, uterus, and bladder.
 
Formulations
EpiPen auto-injectors (epinephrine injections, 1:1000) are available as a 2-pack of 0.3 mL EpiPen auto-injectors and one trainer device. EpiPen Jr auto-injectors (epinephrine injections, USP, 1:2000) are available as a 2-pack of 0.3 mL EpiPen Jr auto-injectors and one trainer device.
 
Adrenaclick epinephrine auto-injectors are available as a carton containing 2 0.3 mg or 0.15 mg auto-injectors. A separate trainer device may be requested through the company’s website or phone center. The authorized generic epinephrine auto-injector of Adrenaclick was released in May 2010, but it isn’t AB rated by the FDA and therefore can’t be interchanged for any other epinephrine product.
 
Product Comparison
Name Formulation Co-pay Card AWP (28 days)
EpiPen Auto-injector Yes: up to $300 savings for each EpiPen 2-Pak carton $730
Epinephrine Auto-injector Yes: max savings of $100
per pack (limit 3 packs)
$494
Adrenaclick Auto-injector No longer marketed
Auvi-Q Auto-injector Recalled in 2015
Twinject Auto-injector Discontinued by manufacturer in 2012
Adrenalin solution Vial N/A $15
Epinephrine HCl solution Vial N/A $1.52
 
Cost based on AWP, per Lexi-Drugs. Cost to the patient will vary based on individual insurance coverage.


Timothy O'Shea, PharmD
Timothy O'Shea, PharmD
Timothy O'Shea, PharmD, is a Clinical Pharmacist working at a large health insurance plan on the east coast. Additionally he works per diem at a retail pharmacy chain. He graduated from MCPHS University - Boston in 2015 and subsequently completed a PGY-1 Managed Care Pharmacy Residency. His professional interests include pharmacy legislation and managed care pharmacy. He can be followed on Twitter at @toshea125.
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