Summary
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. It can not be given by mouth, and inhaled adrenalin is ineffective. 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.

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 or 2 years 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!

Available adrenaline (epinephrine) preparations in Australia
There are 4 commercial preparations of adrenalin available. Your doctor will advise which is most suitable for your needs, and the dose required. Under most circumstances, options 3 and 4 (auto-injectors ) are advised.

1. Needle and syringe

2. Mini Jet device

3. EpiPen auto-injectors

4. Anapen autoinjector (to be released in Australia early 2010)

EpiPen auto-injectors
The EpiPen autoinjector device was originally developed for military use to administer antidotes to poison gas attacks. Each EpiPen 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.

To view a pictorial guide to using EpiPen, click HERE.

To view a pictorial guide to how NOT to use EpiPen, click HERE.

UK-based information on the use of the Anapen device is located HERE

References

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.

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 28 January 2010