Adrenaline (epinephrine, EpiPen) for severe allergic reactions


Adrenaline (epinephrine) is a natural hormone released in response to stress. It is a natural "antidote" to the chemicals released during severe allergic reactions triggered by drug allergy, food allergy or insect allergy. It is destroyed by enzymes in the stomach, and so needs to be injected. When injected, it rapidly reverses the effects of a severe allergic reaction by reducing throat swelling, opening the airways, and maintaining blood pressure. Use of adrenaline for treating anaphylaxis is First Aid.

The principles of management of anaphylaxis treatment are:
1. Identify and avoid the cause (where possible)
2. An Emergency Action Plan to treat accidental exposure

Since episodes of anaphylaxis are unpredictable, a well thought-out "Action Plan" is an essential part of management and should be practiced by the patient and care givers. It requires the patient and their care givers to recognise early warning symptoms, to carry appropriate medication and to be trained in its use.

Use of adrenaline (epinephrine) in anaphylaxis
The body's response to anaphylaxis is to release adrenaline, a natural "antidote" to some of the chemicals released as part of a severe allergic reaction.  Injected adrenaline works rapidly to reduce throat swelling, open up the airways, and maintain blood pressure. It is the only medication available for the immediate treatment of severe allergic reactions.

Potential risks of giving adrenaline (epinephrine)
Common side effects are those of increased heart rate, an increase in blood pressure, thumping of the heart, shaking, nervousness or a transient headache. Of course needles hurt, but you have to remember why you are using it!

Potential Risks of NOT giving adrenaline (epinephrine)
Adrenaline is advised when you have evidence of a potentially life-threatening allergic reaction, such as inability to breathe or a drop in blood pressure. When administered as directed, the risks of not giving adrenaline far outweigh any potential side effects of the medication. Indeed early use of adrenaline has been shown to reduce the need for further doses when people arrive in hospital. Conversely, delayed or no use of adrenalien as been shown to increase the risk of fatal anaphylaxis in our 2016 published study of anaphylaxis fatalities.

Storage of adrenaline (epinephrine)
Adrenaline may be stored at room temperature and does not need to be refrigerated. As long as it is clear (and not brown and cloudy), it is normally safe to use. The shelf life of adrenaline is normally 1 year from the date of supply. You need to check the expiry date from time to time. Automatic injector devices like "EpiPen" have a clear window near the tip where you can inspect the drug.

Where to inject adrenaline (epinephrine)
The adrenaline is best injected into the muscle of the outer mid thigh. Injecting here ensures rapid absorption of adrenaline compared to other potential injection sites, makes it extremely unlikely that damage to any nerves or tendons will occur or that it will be inadvertently injected into an artery or vein (which are deeply buried in the thigh). It is also the least painful part of the body to give an injection! See ASCIA Action Plans online.

Available adrenaline (epinephrine) preparations in Australia
There is only one commercial preparation of adrenaline available - EpIPen. Your doctor will advise which is most suitable for your needs, and the dose required.

Adrenaline auto-injectors
Each device has only one dose of adrenaline. It is designed to be used as a First Aid device by people without formal medical or nursing training.

Adrenaline has a long shelf life

Event expired EpiPens have active adrenaline for a couple of years after their expiry date so keep the old ones as spares for a couple of years after expiry.

Australian PBS subsidy for EpiPen

Up to two devices are subsidised by the Australian PBS. But if a person wants more than 2 devices, the extras need to be purchased privately at full price. There are guidelines available for adrenaline autoinjector prescribing  published by ASCIA.

Using EpiPen

See the ASCIA Action plans listed above.

The steps are:

  1. 1.Hold the EpiPen in your fist, “blue to the sky”

  2. 2.Remove the blue safety cap.

  3. 3.Apply the orange end to the mid outer thigh.

  4. 4.Press hard until the click is hear and HOLD for three full seconds (not 3 “moments”).

eg. count “1 Mississippi, 2  Mississippi, 3 Mississippi”. By pressing hard you are compressing the fat so that the adrenaline goes into the muscle rather than the skin or fat. Keep your thumb as part of the fist as there is no “button” to press at the top of the device.

When you remove the EpiPen, the orange sheath covers the 1 cm long needle; you never actually see a needle. See the pictures below. Also see our article on EpiPen mistakes.


The use of epinephrine in the treatment of anaphylaxis. Position Statement of the American Academy of Allergy, Asthma and Immunology October 1994. J Allergy Clin Immunol 1994; 94: 666-8.

Position Statement. Anaphylaxis in schools and other child-care settings. J Allergy Clin Immunol 1998; 102: 173-6.

Management of children with potential anaphylactic reactions in the community: a training package and proposal for good practice. Clin Exp Allergy 1997; 27: 898-903.

Pumphrey RSH. Lessons for management of anaphylaxis from a study of fatal reactions. Clin Exp Allergy 2000; 30: 1144-50.

Ewan PW. ABC of Allergies: Anaphylaxis. BMJ 1998; 316: 1442-45.

Weir WB, Fred LY, Pike M, Rubakhin SS, Ludwig TJ, Shar AM, Zhu L, Frederick A, Uzoaru I, Wang L, Sweedler JV. Expired Epinephrine Maintains Chemical Concentration and Sterility. Prehosp Emerg Care. 2018 Jul-Aug;22(4):414-418.

doi: 10.1080/10903127.2017.1402109.

Cantrell FL. Epinephrine Concentrations in EpiPens After the Expiration Date. Ann Intern Med. 2018 Jan 2;168(1):82. doi: 10.7326/L17-0496. PMID: 29297030.

Stepensky D, Gorenbein P. Epinephrine Concentrations in EpiPens After the Expiration Date. Ann Intern Med. 2018 Jan 2;168(1):81-82. doi: 10.7326/L17-0494

Cantrell FL, Cantrell P, Wen A, Gerona R. Epinephrine Concentrations in EpiPens After the Expiration Date. Ann Intern Med. 2017 Jun 20;166(12):918-919.doi: 10.7326/L16-0612.

Mullins RJ, Wainstein BK, Barnes EH, Campbell DE.  Increases in anaphylaxis fatalities in Australia 1997 to 2013. Clin Exp Allergy 2016 Aug;46 (8):1 099-110. doi: 10.1111/cea.12748

IMPORTANT The information provided is of a general nature and should not be used as a substitute for professional advice. If you think you may suffer from an allergic or other disease that requires attention, you should discuss it with your family doctor. The content of the information articles and all illustrations on this website remains the intellectual property of Dr Raymond Mullins and cannot be reproduced without written permission.

Last reviewed 3 July 2020

EpiPen device