What is Epinephrine?
Epinephrine, also known as adrenaline, is both a hormone and a medication. A person’s adrenal glands produce epinephrine, which helps to regulate organ functions. It is typically released when the body is under stress. It is part of the fight or flight response. Let’s say something startles you and you feel your pulse racing and the color drains from your skin. That’s all from the release of epinephrine.
But, like many things in medicine, epinephrine has other purposes. Epinephrine medication is a helpful tool in treating medical emergencies. It is the first-line treatment for severe or life-threatening allergic reactions known as anaphylaxis.
Epinephrine is available as a nasal spray, a pre-filled auto-injector, and as a vial that can be used to fill a syringe.
What is epinephrine used for?
When most people think of epinephrine, they think of its use in treating a serious allergic reaction, an anaphylactic episode.
Epinephrine has other uses, primarily to treat heart-related conditions. But these are only used in emergency situations in a hospital. Epinephrine inhalers are sometimes used to treat an asthma attack but not for symptoms of anaphylaxis.
What does epinephrine do?
Epinephrine has different effects on different parts of the body including:
- Heart — it causes the heart to pump faster and harder. This raises your blood pressure and circulates blood more quickly throughout the body.
- Lungs and airways — your breathing becomes deeper and faster. It dilates the airways and may reduce swelling.
- Eyes — it causes the pupils in your eyes to dilate.
- Skin — it becomes pale, as blood is diverted to your major organs and muscles.
- Muscles — they have increased blood flow.
When epinephrine is given, it does all of this simultaneously. It also gives some people the feeling of being hyper or anxious.
All of the above are all normal and expected effects of epinephrine.
Epinephrine for anaphylaxis
Epinephrine is the treatment for anaphylaxis. Anaphylaxis is a severe allergic reaction that can occur due to:
- food allergy
- medication allergy
- insect stings or insect venom allergy
- latex allergy
- vaccine allergy (in rare cases)
Food-induced anaphylaxis is the most common type of anaphylaxis. Anaphylaxis can also occur in people with mast cell diseases, such as mastocytosis or mast cell activation syndrome.
In rare cases, people can experience exercise-induced anaphylaxis. This sometimes can occur after eating food and then exercising vigorously.
People with these allergies and their caregivers need to understand…
- how to prevent allergic reactions;
- how to recognize signs of anaphylaxis;
- how to treat anaphylaxis.
Epinephrine is the first line treatment for an anaphylactic episode.
Epinephrine provides immediate symptom relief. Do not substitute antihistamines for epinephrine. Antihistamines only treat a few symptoms such as hives and they take about 30 minutes to have an effect. Epinephrine will treat a life-threatening allergic reaction immediately – antihistamines will not.
What are the effects of epinephrine when given for anaphylaxis?
You may be asking, why is it so important to use epinephrine for a serious allergic reaction? Well, let’s think about what happens in an anaphylactic reaction. People may experience tongue or throat swelling. They may develop digestive problems or have difficulty breathing. Their blood pressure may drop. They may develop hives or other allergic reaction symptoms.
Epinephrine for anaphylaxis reduces or reverses these severe symptoms very quickly. It opens the airways and reduces swelling. It helps maintain heart function and blood pressure. As epinephrine causes the blood to be diverted away from the skin, it can help reduce hives and itching.
Epinephrine can also prevent a further release of histamine, the chemical that responds to allergens and ushers in symptoms.
Remember that an anaphylactic reaction causes life-threatening symptoms. If not quickly treated, these symptoms can lead to anaphylactic shock and death. Epinephrine works by immediately reversing these severe allergic reactions. So, remember, epinephrine first and epinephrine fast. Don’t delay.
Note: if your symptoms improve and do not return after a dose of epinephrine, then you do not need to call 911 or go to the emergency department. However, if symptoms worsen or come back, then you should take a second dose of epinephrine and call 911 for emergency care.
Sometimes a second dose of epinephrine is needed to treat a second anaphylactic reaction, called biphasic anaphylaxis. Further monitoring from healthcare professionals is necessary.
When do you need an epinephrine injection?
Epinephrine should be given immediately at the first sign of anaphylaxis. Anaphylaxis is diagnosed when symptoms involve two or more body organ systems: skin, mouth and/or throat, stomach, lungs and airways, and heart.
It is crucial to recognize anaphylaxis and treat it immediately. When you see signs of an anaphylactic reaction, administer epinephrine. Death due to anaphylaxis is often due to a delay in giving epinephrine.
What are the symptoms of anaphylaxis?
Anaphylaxis symptoms involve two or more body organs:
- Skin: itching, redness, swelling, hives that are widespread across the body
- Mouth and/or throat: itching, swelling of lips, tongue
- Stomach: vomiting, diarrhea, cramps
- Respiratory: trouble breathing, shortness of breath, wheezing, coughing, chest pain and/or tightness
- Heart: weak pulse, dizziness, faintness
- Headache, nasal congestion, watery eyes, sweating
- Confusion, feeling of impending doom
- Loss of consciousness
How fast does epinephrine work?
Epinephrine begins to work immediately after it is given. However, its full effect may take 5-10 minutes. It can begin to wear off within 20-30 minutes.
Sometimes the epinephrine wears off before the allergic reaction has subsided. Or you may experience a biphasic reaction in which symptoms return. In these cases, a second dose of epinephrine and emergency medical support may be needed.
What is the epinephrine mechanism of action in severe allergic reactions?
Epinephrine triggers a sudden burst of adrenaline to multiple areas of the body simultaneously. Your heart begins to beat faster and stronger. Your airways open. The blood goes to your vital organs and away from your skin.
All of a sudden, you breathe easier. You stop itching and feel less lightheaded, and your pulse stops racing. Epinephrine is so effective, it reverses the life-threatening allergic reaction.
What are the side effects of epinephrine?
Like any medication, side effects from epinephrine may occur. These may include:
- Fast, irregular, or pounding heartbeat
- Pale skin
- Sweating
- Nausea and/or vomiting
- Dizziness
- Weakness or tremors
- Anxiety or restlessness
How long do side effects of epinephrine last?
The side effects don’t last very long. Most of the side effects should start to resolve within about 30 minutes and fully disappear within a few hours.
Is epinephrine dangerous?
When given the correct way and at the correct dose, epinephrine is very safe. As a first-line treatment, epinephrine is the only medication that can reverse life-threatening allergic reaction symptoms.
The concern for the safety of epinephrine is normally due to it being given incorrectly — either a dose too high or by the wrong route of administration.
Can you be allergic to epinephrine?
A true allergy to epinephrine is extremely rare. After all, epinephrine is naturally occurring within the human body. A dose of epinephrine is not going to cause an allergic reaction.
In rare cases, people with an allergy to sulfite preservatives in epinephrine have experienced allergic reactions. Sodium bisulfites are commonly added to epinephrine-containing solutions to serve as an antioxidant and increase the shelf-life for these agents. These allergic reactions are nearly always mild. The benefits of taking the medication far outweigh the risk from an allergic reaction to sulfite. Preservative-free epinephrine is available as well.
Epinephrine is the only medication that can reverse the life-threatening symptoms of an anaphylaxis.
Does epinephrine increase blood pressure?
Epinephrine constricts blood vessels, which can increase blood pressure. But this is only temporary. The effects normally wear off after about 30 minutes.
People diagnosed with heart disease should talk with their doctor about the potential impact epinephrine may have on their condition. If a person with heart disease experiences life-threatening anaphylaxis, epinephrine should still be given.
The benefits of epinephrine in treating life-threatening symptoms far outweigh the risks, even concerning other medical conditions.
Does epinephrine increase heart rate?
Epinephrine raises the heart rate temporarily. This will only last until the medication wears off.
Again, people diagnosed with heart disease should talk with their doctor about the potential impact epinephrine may have on their condition. Epinephrine should still be given to treat life-threatening allergic reactions — the benefits far outweigh the risks.
Is epinephrine a steroid?
Epinephrine is not a steroid. It is a naturally occurring hormone produced by the adrenal glands. As a medication, it is used to treat anaphylaxis.
How is epinephrine given for anaphylaxis?
Epinephrine can be given in multiple ways. It can be delivered using a nasal spray. It can be given using an auto-injector device. Or it can be delivered manually, with the medication drawn from a vial into a syringe.
The nasal spray is delivered only into the nose. Both the auto-injector and manual injection deliver epinephrine into the muscle of the outer thigh. This is referred to as an intramuscular epinephrine injection.
Nasal Spray
The epinephrine in a nasal spray is delivered with a spray into one nostril. If a second dose is needed, use a new device and deliver it into the same nostril.
The epinephrine in the nasal spray is designed to be rapidly absorbed into the nasal passage to reverse the reaction. It temporarily loosens the spaces between the nasal cells to help epinephrine get absorbed into the body.
Injection
The epinephrine in an auto-injector comes pre-filled with epinephrine solution and the needle attached. All it requires is the user to follow the auto-injector instructions to release the epinephrine into the muscle of the outer thigh.
Using the manual method, the epinephrine would first need to be drawn up from a vial into a syringe. Then you would attach a needle to the syringe. This process creates room for error and takes longer. It could delay the emergency treatment. (Some syringe kits do come pre-filled with the epinephrine solution and needle attached. Ask your doctor if these kits are available.)
Epinephrine auto-injectors are considered more user friendly than the manual method. They leave less room for error.
Some people may choose to use the manual method because it’s a much cheaper alternative than epinephrine auto-injectors. Epinephrine auto-injectors may cost anywhere from $100 to several hundred dollars, depending on insurance. Meantime, ampules of epinephrine and syringes/needles can be purchased for around $20.
Other routes of administration
Clinical trials are underway for new routes of epinephrine administration to treat severe reactions. Sublingual epinephrine (under the tongue) shows promising results for treating anaphylaxis.
Is there a general epinephrine dose for anaphylaxis?
The dosage depends on the device used:
Epinephrine Nasal Spray (neffy®)
- Dosage (spray in nostril): 2 mg for over 66 pounds
Epinephrine auto-injectors (EpiPen®, AUVI-Q® and generics)
- Adult Dosage (injection in outer middle of thigh): 0.3 mg for people over 66 pounds
- Children’s Dosage (injection in outer middle of thigh): 0.10 mg (for children 16.5 to 33 pounds) — AUVI-Q brand only; 0.15 mg (for children under 66 pounds); 0.3 mg (for children over 66 pounds)
Hospitals and emergency departments typically use vials and syringes to administer epinephrine. When prescribing epinephrine, hospital and emergency room staff will provide a specific dosage based on the patient’s body weight.
How is epinephrine administered in an emergency?
Give epinephrine at the first sign of an anaphylaxis emergency. If you aren’t sure if it’s anaphylaxis, give epi anyway! Epinephrine is generally safe and effective, even if given when not needed. It can cause side effects such as anxiety, dizziness, shakiness, headache, and nausea, but these are usually mild and not life-threatening.
Epinephrine nasal sprays are taken with a spray into the nose. Auto-injectors and syringes are given via intramuscular injection into the middle outer thigh muscle. Follow the instructions for your specific brand.
There is no need to remove clothing to administer epinephrine injections. Give it right through the clothes if necessary.
If your symptoms improve after the first dose of epinephrine and you’re feeling better, you don’t need to go the hospital or emergency department. However, you should call for emergency medical help or go to the hospital or clinic if…
- symptoms return or worsen after the first dose of epinephrine.
- you have severe anaphylaxis;
- symptoms do not go away promptly or completely after the first dose of epinephrine.
How do you use an epinephrine nasal spray?
The process for using an epinephrine nasal spray is as follows:
- Insert the nozzle of the nasal spray fully into one nostril.
- Hold the nasal spray straight into the nose.
- Do not angle it against the inside or outside wall, as this could cause you to lose some of the medication.
- Press the plunger firmly to activate the device and deliver the epinephrine.
- Avoid sniffing during and after taking the medicine.
The medication is given as a single dose.
It’s important to always carry two epinephrine nasal spray devices. You may need a second dose if your symptoms continue or come back.
If a second dose is needed, use a new nasal spray. Insert it into the same nostril you used for the first dose. Do not reuse the nasal spray you used for the first dose. The second dose should be taken at least five minutes after the first dose.
How do you inject epinephrine?
Each epinephrine auto-injector brand may function differently. Familiarize yourself with your specific type of auto-injector. Review the package instructions. Ask your doctor for anaphylaxis education resources. Generally, the process for administering an epinephrine auto-injector is as follows:
- Take off the cap.
- Press the tip firmly on the thigh at a perpendicular (right) angle.
- Swing and push the auto-injector firmly until you hear a click.
- Hold firmly for 2-10 seconds (this varies depending on the device)
- Remove the auto-injector.
- Massage area for 10 seconds.
- Monitor symptoms.
- If symptoms are severe, or they worsen or come back (called biphasic anaphylaxis), go to the hospital or emergency department for follow-up care.
- Discard the auto-injector (preferably in a sharps container, which you can get at any pharmacy). Bring it with you if you go to the hospital or emergency room.
Are epinephrine auto-injectors the same dosage?
No, epinephrine auto-injectors come in doses based on body weight:
- 0.10 mg (for children 16.5 to 33 pounds) — AUVI-Q brand only
- 0.15 mg (for children under 66 pounds)
- 0.3 mg (for children and adults over 66 pounds)
How to use a generic epinephrine auto-injector?
Generic epinephrine auto-injectors may have slightly different instructions. It is important to review the instructions for your specific device. In general, the process is very similar to most brand name auto-injectors:
- Take off the cap.
- Press the tip firmly on the thigh at a perpendicular angle.
- Swing and push the auto-injector firmly until you hear a click.
- Hold firmly for 2-10 seconds (this varies depending on the device)
- Remove the auto-injector.
- Massage area for 10 seconds.
- Call 911 for continued monitoring and in case you need a second injection to treat biphasic anaphylaxis.
- Discard auto-injector or bring it with you when going to the hospital or emergency room.
Where should auto-injectors be injected?
Epinephrine auto-injectors should be injected directly into the muscle of the middle outer thigh. Do not inject into veins, the arm, or the buttocks. For young children, you may need to hold the leg firmly in place during injection to help prevent injuries.
Is an auto-injector an EpiPen?
An EpiPen® is an auto-injector, but not all auto-injectors are EpiPen. EpiPen and EpiPen Jr® are brand name epinephrine auto-injectors made by Viatris (formerly Mylan). There are other epinephrine auto-injectors on the market including:
- AUVI-Q®
- Adrenaclick®
- Several generic options
Visit our online store to download our free Epinephrine treatment poster or purchase print copies.
How much epinephrine is in an EpiPen?
EpiPen contains 0.3 mg of epinephrine. EpiPen Jr. contains 0.15 mg of epinephrine.
Are epinephrine auto-injectors interchangeable among users?
Different brands of auto-injectors should not be used interchangeably among users. They each may have slight differences in how they are administered. Using them interchangeably could result in an error if a person is not familiar with the particular brand.
However, in an anaphylaxis emergency — if the choice is between no epinephrine or using a different brand, use the different brand. Then call 911.
When to give second dose of epinephrine?
A second dose of epinephrine should be given if symptoms persist 5-15 minutes after the first dose is administered. Sometimes symptoms reemerge between 8 and 72 hours after the first injection. These are called biphasic anaphylactic reactions.
You should call 911 or go to your nearest emergency department for follow-up medical care if you need to administer a second dose of epinephrine.
Is epinephrine expensive?
The cost of epinephrine varies depending on the brand you’re prescribed and your insurance coverage.
Whether you use a nasal spray or auto-injector, epinephrine can be expensive. The cost is normally from around $100 to several hundred dollars. Some people may pay up to $600. Many of the manufacturers offer copay assistance cards or discounts.
The epinephrine nasal spray neffy® is available for $25 for each prescription for people who have private health insurance that covers it. This is through a co-pay savings program.
Ampules of epinephrine with a syringe and needle are much cheaper, at around $20. But they are not as user-friendly as an auto-injector and they usually take more time to administer. This could delay emergency treatment.
If you are concerned about the cost of epinephrine, talk with your healthcare provider. Here are some steps you can take to find ways afford your epinephrine.
What does an epinephrine auto-injector cost?
Costs may differ between brands. In general, epinephrine auto-injectors can cost anywhere from $100 to $600. This depends on health insurance coverage and the use of any patient assistance programs.
What are the contraindications for epinephrine?
Epinephrine is the only medication that has no contraindications for treating anaphylaxis. This means there is no medical condition or factor that serves as a reason to withhold epinephrine. The benefit of preventing death from anaphylaxis far outweighs any potential health risks.
Healthcare providers and patients should be aware of and discuss the potential impact epinephrine may have on other medical conditions, such as heart disease. But it doesn’t matter what other medical condition is present, because anaphylaxis is a life-threatening situation and epinephrine is the only treatment for it. There is no alternative.
Can students self-carry their epinephrine in school?
All 50 states allow students to self-carry and administer epinephrine in school. If your age-appropriate child needs to self-carry epinephrine, make sure to coordinate with the school nurse and/or teachers.
Can school nurses administer epinephrine?
The School Access to Emergency Epinephrine Act permits trained school staff to give epinephrine to anyone having a life-threatening allergic reaction. The law also allows schools to stock emergency supplies of epinephrine in an easily accessible and secure location.
School nurses are specially trained in both administering epinephrine and identifying allergic reactions. Teachers should also be trained since they are often the first to recognize symptoms.
Are epinephrine devices available in public places?
Thirty-five states have passed stock epinephrine entity laws for public places. In general, these laws allow — but do not require — public venues to maintain an emergency supply of epinephrine devices. Public venues may include:
- Restaurants
- Theme parks
- Sports arenas
- Shopping malls
- Hotels
- Day camps
Depending on the state, the laws may allow for public venues to provide anaphylaxis training to employees. They may also protect the public venue from civil liability.
How should you store epinephrine?
- Store your epinephrine devices as close to room temperature as possible. This is between 68 to 77 degrees F. Do not leave the devices in extremely hot or cold temperatures. This can make auto-injectors ineffective or cause the device to malfunction. Storage of the epinephrine nasal spray at high temperatures of up to 122 degrees is allowed for a few days. But if the epinephrine nasal spray freezes, it will not spray the medication when needed.
- Keep auto-injectors out of direct sunlight. This can cause the epinephrine to oxidize (combine with oxygen, changing the makeup of the drug) and become ineffective. Oxidized epinephrine will appear dark or have solid particles in it. Epinephrine can also oxidize on its own over time, so check your device regularly to be sure the liquid inside is clear.
- Check expiration dates. Epinephrine should be replaced as soon as it expires. However, if all you have is an expired device in an emergency, use it anyway. It may provide some benefit. Check the date on your devices regularly, including backups that may be in a school nurse’s office or at a family member’s house.
What if I am unsure if I’m having anaphylaxis or a severe asthma attack?
If you live with asthma and are also at risk for anaphylaxis due to a severe allergy, it is important to recognize symptoms and know what to do in an emergency.
When symptoms first occur, it may be difficult to know if you are experiencing anaphylaxis or an asthma attack. Symptoms of an asthma attack — coughing, wheezing, chest tightness, shortness of breath — may be similar to anaphylaxis.
If you are unsure if it’s asthma or anaphylaxis, you should assume it is anaphylaxis and treat symptoms immediately with epinephrine. Don’t use your inhaler first and see if it helps resolve symptoms. There have been numerous deaths of people who used their inhaler first and delayed giving epinephrine.
After you have administered epinephrine, you can try using your inhaler. If symptoms persist, you may need to call 911 for emergency medical treatment.
Can an epinephrine inhaler be used for anaphylaxis?
Epinephrine inhalers are sometimes used to treat symptoms of asthma, but not anaphylaxis. These medications are available over the counter. Common brand names include Primatene Mist® or EpiMist. Epinephrine inhalers are not an appropriate substitute for epinephrine injectors or nasal sprays to treat anaphylaxis. The amount of epinephrine in an inhaler will not work for people having an anaphylactic reaction.
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Supported by:
Reviewed by:
Bradley Chipps, MD, FACAAI, is a board-certified allergist and pediatric pulmonologist with Capital Allergy and Respiratory Disease Center in Sacramento, California. He earned his medical degree from University of Texas Medical Branch in Galveston in 1972. He is Past President of the American College of Allergy, Asthma and Immunology (ACAAI).
