Epinephrine auto-injector


Epinephrine is in a class of medications called sympathomimetic agents because the medication mimics the properties of the sympathetic nervous system. Epinephrine is a medication used in emergencies to treat or prevent severe allergic reactions that can result in anaphylaxis.
Anaphylaxis is a rapid, immune-mediated (allergic), systemic reaction to allergens (like food, medication or insect stings or bites) that the individual has previously been exposed to. Anaphylaxis can be potentially life threatening. The most dangerous symptoms are low blood pressure, breathing difficulties, shock and loss of consciousness, all of which can be fatal. The most severe type of anaphylaxis, known as anaphylactic shock, usually results in death within minutes, if untreated. Anaphylactic shock is characterized by inflammation of the throat and a sudden drop in blood pressure.
Epinephrine is administered to improve breathing, stimulate the heart and reduce facial swelling during a severe allergic reaction. Epinephrine relaxes the muscles in the airways and tightens the blood vessels.
Individuals who are at risk for anaphylaxis, such as individuals allergic to bee stings, carry a prescription epinephrine auto-injector. If symptoms of anaphylaxis appear after exposure to an allergen, the patient uses the device to inject the epinephrine into his/her thigh. A trained family member of friend may help the patient administer the epinephrine, if necessary.

Related Terms

Allergy, allergic reaction, anaphylactoid reaction, anaphylatoxin, autoinjectable epinephrine, bee sting, bronchospasm, cardiovascular collapse, drug allergy, epinephrine, food allergy, hives, hymenoptera stings, hypotension, immunologic reaction, insect sting, insect venom, passive transfer, penicillin, pseudo-anaphylaxis, respiratory arrest, sympathetic nervous system, sympathomimetic agents, sympathetic nervous system true anaphylaxis.

brand names

Adrenaline®, Epi E-Z Pen®, EpiPen® Auto-Injector, EpiPen Jr. Auto-Injector®, Primatene®.

how to use the device

Epinephrine auto-injectors are disposable, one-time-use devices, which contain a single dose of epinephrine. Use epinephrine injection exactly as directed.
An epinephrine auto-injector is self-administered by way of injection. Some individuals, especially children, may need assistance administering the medication. It is recommended that friends and family members of the patient learn how to properly administer the medication, in case of an emergency.
To use, remove the safety cap, and remove the auto-injector from its storage tube.
Hold the device with the black tip facing downward.
Release the safety cap with the other hand.
Swing and jab the auto-injector into the outer thigh until the device clicks. The auto-injector should be at a 90-degree angle to the thigh. The needle may be injected through clothing that is covering the thigh.
Hold the device firmly against the thigh for about 10 seconds. The injection is now complete.
Remove the device from the thigh and rub the area with the hand.
Carefully place the auto-injector, needle-end first, into the storage tube. Screw the cap. Go the nearest hospital emergency room immediately. Bring the auto-injector, and tell the physician that the device was used. The physician will dispose of the device.
If the epinephrine is accidentally injected into any part of the body other than the thigh, go to the nearest hospital emergency room immediately.

who should carry one

Individuals who have experienced severe allergic reactions in the past or have known allergies that may cause anaphylaxis should consult their healthcare providers to determine whether an epinephrine auto-injector should be prescribed. Severe allergic reactions are most commonly triggered by food (especially peanuts, shellfish, fish, milk and eggs), insect stings/bites, latex and medications (especially antibiotics and anti-seizure medicines).

side effects

Side effects may include upset stomach, vomiting, sweating, dizziness, nervousness, weakness, pale skin, increased blood pressure, headache and shaking. The effects of the injection begin to wear off after 10 to 20 minutes.
Serious side effects may include difficulty breathing or irregular heartbeat. These symptoms are rare, and patients should call their healthcare provider immediately if they experience them.


Patients should tell their qualified healthcare providers if they have heart conditions, high blood pressure, thyroid disease or allergies (especially drug allergies) because epinephrine can potentially worsen their conditions. Patients should also tell their doctor if they have diabetes because epinephrine can potentially increase or decrease the blood-glucose-lowering effect of insulin.
Patients should inform their healthcare providers if they are taking any prescription or over-the-counter medication, vitamins, nutritional supplements or herbal supplements.
Pregnancy: Patients who are pregnant or thinking about becoming pregnant should consult their healthcare providers. It is unknown whether epinephrine is excreted in breast milk. Patients are advised to consult a qualified healthcare provider to discuss the risks and benefits of using epinephrine during pregnancy or breastfeeding.


The epinephrine auto-injector should be kept inside the plastic carrying tube and out of reach of children.
Store the medication in a dark place at room temperature. Avoid exposure to heat and moisture.
Dispose of the device once the expiration date has passed or if the liquid has changed color, is cloudy or contains solid particles.