Updated May 24, 2015.
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Injectable epinephrine is the treatment of choice for anaphylaxis from any cause – with food allergy being the most common cause. Other common causes of anaphylaxis include venom allergy, latex allergy, drug allergy, exercise and unknown causes (idiopathic). Epinephrine may also be used for angioedema, particularly if it involves the face and obstructs a person’s ability to breathe and severe asthma attacks.
In fact, injected epinephrine very commonly used to treat asthma before the development of inhaled medications many decades ago. Inhaled epinephrine is still occasionally used to treat asthma attacks, was previously available as Primetine Mist CFC-inhaler, and is still available as Asthmanefrin Nebulizer Solution. However, the side effects of inhaled epinephrine are more than that of inhaled albuterol, and therefore inhaled albuterol is the preferred treatment for the acute symptoms of asthma.
There are various brands of pre-filled injectable epinephrine devices, with the Epi-Pen being the most popular. Adrenaclick is another brand; the device works similar to the Epi-Pen. Auvi-Q is a newer device that has voice commands to assist the user in the correct administration of epinephrine. There are two doses available for each device – the “adult” dose of 0.3 mg of epinephrine is for children and adults weighing more than 66 pounds, and the “junior” dose of 0.15 mg of epinephrine for children weighing between 33 and 66 pounds.
Typically, doctors also prescribe the junior dose of epinephrine for children weighing less than 33 pounds, since there isn’t a lower dose of pre-filled injected epinephrine available.
When I see new patients in my office who have experienced anaphylaxis, or are at increased risk of anaphylaxis, I’m often surprised to see how many of these patients either don’t have injectable epinephrine prescribed to them, or they have no idea when and how to use their injectable epinephrine. I often tell my patients that injectable epinephrine is like an insurance policy – you don’t buy insurance because you’re planning on using it – rather you buy insurance because you’d rather have it and not need it, as opposed to needing it and not having it. As long a person knows when (symptoms of anaphylaxis) and how (technique is very important) to use it, having injectable epinephrine is never wrong for a person at risk for anaphylaxis.
Many people who are at risk for anaphylaxis are never actually prescribed injectable epinephrine. For this reason, in 2013 a group of researchers at Mount Sinai School of Medicine in New York City sought to determine what types of patients are prescribed injectable epinephrine, and for what medical diagnoses it is prescribed. The overwhelming majority of injectable epinephrine prescriptions (nearly 60%) were given for food allergy. Angioedema accounted for nearly 10% of prescriptions. The remaining 30% of prescriptions were given for other conditions such as venom allergy, asthma and hives.
The majority of injectable epinephrine prescriptions (nearly 80%) were given by non-allergist physicians, but only two out of three of these patients were actually referred to an allergist for medical evaluation. Primary care doctors amounted for nearly all prescriptions for injectable epinephrine for the diagnosis of venom allergy (94%), but none of these patients were referred to an allergist for evaluation and treatment with venom immunotherapy – which is the standard of care for venom allergy.
This study supports the fact that injectable epinephrine is generally prescribed by various types of doctors for people who are at increased risk for anaphylaxis. However, not all of these patients are referred to an allergist for appropriate allergy testing and further treatment, particularly those with venom allergy. And, in my experience, very few patients are appropriately taught when and how to correctly use their injectable epinephrine. In my opinion, any person who has been prescribed injectable epinephrine, or has experienced anaphylaxis, should be seen by an allergist for a medical evaluation.
Find out if you should ever use an expired Epi-Pen.
Source:
Agarwal S, Wang J. Prescribing Trends of Epinephrine Auto injectors Within an Urban Population. J Allergy Clin Immunol Pract. 2013;1:681-2.
DISCLAIMER: The information contained in this site is for educational purposes only, and should not be used as a substitute for personal care by a licensed physician. Please see your physician for diagnosis and treatment of any concerning symptoms or medical condition.