Epinephrine (Adrenaline)

Epinephrine (Adrenaline) Overview

Epinephrine is the emergency medicine for anaphylaxis, a sudden, life-threatening allergic reaction. It is used for severe reactions to insect stings, foods, medications, latex and other triggers, together with emergency medical care (MedlinePlus). It is not a treatment for everyday seasonal allergy symptoms like sneezing or itchy eyes; those are treated with medicines such as antihistamines and nasal steroid sprays.

In this article we explain what epinephrine is, how it works, how it’s given, and how to store and carry it. For device-specific tips, see our EpiPens guide.

Epinephrine

Epinephrine, also called adrenaline, is a hormone your body makes naturally as part of the “fight or flight” response. As a medicine, it can reverse the dangerous effects of anaphylaxis within minutes.

How Does It Work?

Epinephrine relaxes the muscles in the airways and tightens the blood vessels, which helps open the airways and raise dangerously low blood pressure (MedlinePlus). For anaphylaxis, it is usually injected into the muscle of the outer thigh with an auto-injector. Since August 2024 there is also a needle-free option: the FDA approved neffy, an epinephrine nasal spray, for adults and children who weigh at least 30 kg (about 66 lb) (FDA).

It works by acting on alpha- and beta-adrenergic receptors in the body (MedlinePlus).

Benefits of Epinephrine

Besides treating anaphylaxis, epinephrine has other medical uses that are handled by doctors in hospitals, such as treating dangerously low blood pressure from septic shock (MedlinePlus). Other hospital uses include:

• Given to a patient with cardiac problems
• Given to a patient in cardiac arrest
• Used by clinicians in some severe breathing emergencies
• Used by clinicians in some severe cases of Croup
• It is used in conjunction with anesthesia to prolong its effect

For people with allergies, its key role is as the first and most important treatment for anaphylaxis. The FDA notes that epinephrine is the only life-saving treatment for anaphylaxis.

Side Effects

Like any medicine, epinephrine can cause side effects. They are usually short-lived, and the risk of not treating anaphylaxis is far greater.

Following are the side effects of Epinephrine:

• skin redness, swelling, warmth, or tenderness at the site of injection
• difficulty breathing
• pounding, fast, or irregular heartbeat
• nausea
• vomiting
• sweating
• dizziness
• nervousness, anxiety, or restlessness
• weakness
• pale skin
• headache
• involuntary shaking of a body part

After using epinephrine, always get emergency medical treatment right away and tell the medical team about any side effects (MedlinePlus).

Normal Dosage of Epinephrine

Your doctor prescribes the right device and dose for you or your child, often based on body weight. Use epinephrine exactly as prescribed, inject it at the first sign of a serious allergic reaction, and inject only into the middle of the outer thigh (it can go through clothing in an emergency) (MedlinePlus).

Keep two devices with you at all times, because one dose may not be enough. If symptoms continue or come back, your doctor may tell you to use a second dose with a new device. Only a healthcare provider should give more than two doses for a single episode (MedlinePlus).

Children usually need a different device strength than adults, so ask your doctor which one is right for your child.

Overdosage

Using more epinephrine than prescribed can cause an overdose. Symptoms may include (MedlinePlus):

• sudden weakness or numbness on one side of the body
• sudden difficulty speaking
• slow or fast heart rate
• shortness of breath
• Rapid respiration
• Confusion and uncertainty
• tiredness or weakness
• cold, pale skin
• decreased urination

An overdose is a medical emergency.

Treatment for Overdose

In case of overdose, call Poison Control at 1-800-222-1222. If the person has collapsed, had a seizure, has trouble breathing or can’t be woken up, call 911 immediately (MedlinePlus). Treatment is given by emergency medical staff.

Storage and Disposal of Epinephrine

Keep the auto-injector in the plastic carrying tube it came in, at room temperature, away from light, heat and moisture. Do not refrigerate it or leave it in your car. Check the expiration date and replace it when it passes, and look at the solution from time to time; if it is discolored or has particles, get a new device (MedlinePlus).

Disposal

If a device is dropped, check whether it is broken or leaking, and replace any damaged device right away (MedlinePlus).

Don’t throw used or expired devices in the trash or flush medicine down the toilet. Take a used device with you to the emergency room, or ask your pharmacist about a take-back program (MedlinePlus).

Conclusion

Epinephrine is the emergency treatment for anaphylaxis, not for routine seasonal allergy symptoms. If you have a history of severe allergic reactions, carry two doses, know how to use them, and always call 911 after using one. Learn the warning signs in our seasonal allergy emergency guide and the differences between life-threatening and seasonal allergies.

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Written by: Madiha Ather Hashmi (May 19, 2020)

This article is for general education and is not medical advice. Talk with your doctor or pharmacist about your symptoms and before starting, stopping, or combining any medicine.

Epinephrine FAQs

Is epinephrine used for seasonal allergies?

No. Epinephrine treats anaphylaxis, a life-threatening reaction. Everyday seasonal allergy symptoms are treated with antihistamines, nasal steroids and other medicines (MedlinePlus).

Is there an epinephrine option without a needle?

Yes. In August 2024 the FDA approved neffy, an epinephrine nasal spray, for people who weigh at least 30 kg (about 66 lb) (FDA).

Why should I carry two doses?

One dose may not be enough, and symptoms can return. Doctors advise keeping two devices available at all times (MedlinePlus).

Do I still need the ER after using epinephrine?

Yes. Get emergency medical treatment immediately after using epinephrine (MedlinePlus).

Sources

Looking for more treatment options? Find a full list of other seasonal allergy treatment options here.