EpiPen® auto injectors are automatic injection devices containing adrenaline
for allergic emergencies.


Anyone at risk of an anaphylactic reaction should carry an adrenaline auto-injector with them at all times1, as an immediate injection of adrenaline could be the difference between life and death.

NICE guidelines recommend that all patients admitted with a confirmed or suspected anaphylactic reaction should be prescribed an adrenaline auto-injector while awaiting specialist referral.2

European guidelines provide the following absolute and relative indications for prescribing adrenaline auto-injectors in children.3

Absolute indications

  • Previous cardiovascular or respiratory reaction to a food, insect sting or latex.
  • Child with food allergy and co-existent asthma.
  • Exercise induced anaphylaxis.
  • Idiopathic anaphylaxis.

Relative indications

  • Any reactions to small amounts of a food (e.g. airborne food allergen or contact only via skin).
  • History of only a previous mild reaction to peanut or tree nut.
  • Remoteness of home from medical facilities.
  • Allergic reaction to food as a teenager.

People who have been prescribed an adrenaline auto-injector because
of the risk of anaphylaxis should carry two with them at all times for emergency, on-the-spot use.4

35% of patients may require more than one adrenaline dose.5 
As many as 20% of patients will go on to develop a biphasic anaphylactic response many hours later.6


Anaphylaxis is unpredictable, and while a person may have a mild reaction one time, a serious or even life-threatening reaction can occur the next time. In addition, allergic reactions can begin with mild symptoms and then progress to a full anaphylactic episode.

A person who is having an allergic reaction should use their EpiPen® immediately if they experience ANY of the following serious symptoms of anaphylaxis following contact with their allergen:

  • difficulty/noisy breating
  • swelling of the tongue
  • swelling/tightness in throat
  • difficulty talking and/or hoarse voice
  • wheeze or persistant cough
  • loss of consciousness and/or collapse
  • pale and floppy (young children)

Patients experiencing the following mild to moderate symptoms of anaphylaxis should take an anti-histamine and have their EpiPen® ready in case of worsening symptoms:

  • red raised itchy rash
  • swelling of face/lips/eyelids
  • being sick
  • stomach ache

It is important to note that not all patients will have all reactions, and an individual may experience a different set of symptoms during different episodes, even if the same trigger is involved.

There is clear evidence that failing to administer adrenaline as soon as anaphylaxis is suspected has contributed to fatal outcomes.7 Delayed injection of adrenaline can also increase the likelihood of a biphasic reaction.9

It is recommended that at risk patients carry 2 EpiPen® at all times. A second dose can be given after about 5 minutes if necessary.4


It is important to familiarise yourself with how to use the EpiPen® so that you can show your patients. Various studies have shown that many patients (or parents of patients) do not use their pen properly, or in some cases at all, because they have not had sufficient training.10, 12,

The procedure is shown below:
Lie down with your legs slightly elevated or sit up if breathing is difficult.

It is important to impress on patients the need to call 999 immediately, as EpiPen® is not a curative treatment for anaphylaxis, but allows patients time to get to hospital where they can receive appropriate medical care.

Patients should stay lying down or seated and have someone stay with them until they have been assessed by a paramedic.14

Unconscious patients should be placed in the recovery position.14

MEDA Pharmaceuticals Ltd has produced various items to help you support your patients, including how to use leaflets, EpiPen® Demonstration Video and Trainer Pens, which are available from the Supporting Patients section of this website.


If used correctly, significant injury with EpiPen® is unlikely. Patients should not remove the blue safety cap until they are ready to inject, always ensure that they point the end with the orange tip towards the thigh and never put their thumbs or fingers over the orange tip. Directions for use are in the package insert.14

EpiPen® should only be injected into the anterolateral aspect of the thigh, NOT ANY OTHER PART OF THE THIGH OR BUTTOCK. The outer thigh is the safest site for IM injection as there is minimal risk of injection into major blood vessels or nerves in this area. Intravascular injection (which is possible on the front of the thigh) could lead to acute cardiovascular compromise. Injection into a major nerve (which could occur on the posterior thigh or buttock) can cause significant damage; also, injection into the buttock may not be effective for a severe allergic reaction. Accidental injection into the hand, particularly the digits, can cause serious injury and possibly gangrene. This injury needs to be urgently assessed and treated in an emergency room.14, 15

Potential side effects include an increase in heart rate, a stronger or irregular heartbeat, sweating, nausea and vomiting, difficulty breathing, paleness, dizziness, weakness or shakiness, headache, apprehension, nervousness, or anxiety. However, these side effects usually subside quickly, especially if the patient rests.14, 15

EpiPen® should be used with caution in patients with high blood pressure and thyroid conditions (as side effects can last longer) and in pregnancy; furthermore, sensitisation of the heart to catecholamines may occur in patients with uncontrolled hyperthyroidism or those using cocaine.1 Blood sugar may increase in patients with diabetes and symptoms can temporarily get worse in patients with Parkinson’s disease.15

Overdose of adrenaline is unlikely with EpiPen®. However, symptoms of overdose are elevated arterial pressure, pulmonary oedema and cardiac arrhythmias. If necessary, pressor effects may be counteracted by rapidly acting vasodilators or alpha-adrenergic blocking drugs.14

It is important to remember that in practice there are no known contraindications to IM adrenaline use in a life-threatening allergic reaction.14

If you have any concerns/questions about the safety aspects of EpiPen®, please call +44 (0) 1707 853000, then chose Option 1 for the Medical Information Department, or send an email to info@mylan.co.uk


  1. Resuscitation Council (UK) Guidelines. January 2008.
    Available at: http://www.resus.org.uk/pages/reaction.pdf Last accessed January 2018.
  2. NICE clinical guideline 134. Anaphylaxis: assessment to confirm an anaphylactic episode and the decision to refer after emergency treatment for a suspected anaphylactic episode. Issued December 2011.
  3. Muraro A, Roberts G, Clark A, et al. Allergy 2007;62:857–871.
  4. Drug Safety Update Volume 11 Issue 1, August 2017: A3.
  5. Korenblat P et al. Allergy Asthma Proc. 1999;20(6):383-386.
  6. Kemp SF et al. World Allergy Org J 2008;1(7):S18-S26.
  7. Pumphrey RS. Clin Exp Allergy.2000;30(8):1144-1150.
  8. .
  9. Simons FER.J Allergy Clin Immunol 2010;125:S161-81.
  10. Gold MS, Sainsbury R.F J Allergy Clin Immunol 2000;106:171-6.
  11. Allen CW et al. Med J Austral 2007;187(9):542.
  12. Kim JS et al. J Allergy Clin Immunol 2005;116:164-8.
  13. Diwakar L et al. J Investig Allergol Clin Immunol 2010;20(5):446-53.
  14. EpiPen Summary of Product Characteristics, © Meda Pharma GmbH, a Mylan company 2018, January 2018. 
  15. EpiPen US Prescribing Information, Dey, LP, May 2016.

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