Epinephrine (EpiPen) – Injection

What Is EpiPen?

EpiPen is a prescription auto-injector device that contains epinephrine, a chemical that narrows blood vessels and opens airways in your lungs. Epinephrine is an alpha- and beta-adrenergic agonist (sympathomimetic agent).

It works quickly to open airways in the lungs by relaxing the muscles and tightening the blood vessels to improve breathing, stimulate the heart, raise blood pressure, reverse hives, and reduce swelling of the face, lips, and throat.

EpiPen is used along with other emergency medical treatments to treat life-threatening allergic reactions. It’s a prefilled, handheld device that automatically injects a measured dose of medicine through self-injection.

Drug Facts

Generic Name: Epinephrine

Brand Name(s): EpiPen, EpiPen Jr

Drug Availability: Prescription

Therapeutic Classification: Alpha- and beta-adrenergic agonist; Sympathomimetic agent

Available Generically: Yes

Controlled Substance: N/A

Administration Route: Injection

Active Ingredient: Epinephrine

Dosage Form(s): Injectable

What Is EpiPen Used For?

EpiPen auto-injectors are used to:

  • Relieve troubled breathing (respiratory distress) from tightening bronchial muscles (bronchospasm)
  • Relieve severe allergic reactions from exercising (exercise-induced anaphylaxis)
  • Relieve severe allergic reactions to insect stings or bites, foods, drugs, and other allergens (anaphylactic shock)
  • Relieve low blood pressure (hypotension) due to septic shock
  • Prolong the effect of medicines that reduce pain before surgery (infiltration anesthetics)
  • Act as a primary drug given during cardiopulmonary resuscitation (CPR) to reverse a stopped heart (cardiac arrest)

Anaphylaxis is a serious allergic reaction that occurs in around one out of 50 people in the United States. Symptoms can arise very quickly. Using epinephrine in the early stages of an anaphylaxis episode may decrease hospitalization rates, prevent low blood pressure, and increase the odds of survival.

How to Use the EpiPen

Read all patient information and instructions before using your EpiPen. If you have any questions, ask your healthcare provider.

Keep your EpiPen near you at all times. Do not open the safety cap unless you are ready to inject it. From time to time, make sure that the solution inside is clear. The medicine solution should have no particles and no discoloration. If it has turned cloudy, pink or brown in color, do not use it. Discard and replace it with a new one.

Different brands of epinephrine have different directions for preparing and injecting the medicine. Learn how to inject correctly to be ready if you need to use it. Ensure a family member, caregiver, or any other responsible person knows where you keep your EpiPen and how to inject it for you in case of emergency. Your dosage will vary depending on your medical condition, weight, and response to treatment in different individuals.

Inject EpiPen into your thigh as directed by your healthcare provider or the manufacturer. EpiPen can be injected through clothing in an emergency if needed. Epinephrine acts quickly but does not last long. After injecting the epinephrine, seek medical help. Tell your health care provider that you have given yourself an epinephrine injection.

Avoid injecting EpiPen into the hands, feet, buttocks, or other areas of the body. If you have accidentally injected somewhere other than the thigh, get medical help right away. While injecting infants and young children, be sure to hold the child's leg firmly to prevent injury. Discard the injector properly after use.

Storage

Store this product in the plastic carrying case that it comes in. Keep at room temperature (between 68 and 77 degrees Fahrenheit) and away from light and moisture. Do not store an EpiPen in your vehicle's glove box or keep it in the bathroom. Do not refrigerate or freeze it.

Check the expiration date regularly. If the prefilled automatic injection device is dropped, make sure that it’s not broken or leaking. Dispose of the damaged device and be sure to have a replacement available. 

Keep all medications locked and away from the sight and reach of children and pets.

Do not flush expired medications down the toilet or pour them into a drain unless instructed to do so. Discard the unwanted medications properly when they’re expired or no longer needed. Contact your pharmacist or local waste disposal company for a medicine-take-back program.

If you plan to travel with your EpiPen, get familiar with your final destination's regulations. In general, be sure to make a copy of your EpiPen prescription. If possible, keep your medication in its original container from your pharmacy with your name on the label. If you have any questions about traveling with your medicine, be sure to ask your pharmacist or healthcare provider.

How Long Does EpiPen Take to Work?

Epinephrine acts quickly but does not last long. Be sure to check with your healthcare provider or pharmacist if you've any questions.

Off-Label Uses

Off-label uses of epinephrine include:

  • Ventricular fibrillation (a dangerous type of irregular heartbeat that affects the heart's ventricles)
  • Pulseless ventricular tachycardia (a life-threatening cardiac arrhythmia, a problem with heart rate or speed) 
  • Pulseless electrical activity (PEA) (a clinical condition in which a person is unresponsive and doesn’t have a detectable pulse)
  • Croup (an infection of the upper airway making breathing difficult and causing a cough that sounds like a bark)
  • Severe asthma that doesn’t respond to regular treatment

What Are the Side Effects of EpiPen?

This is not a complete list of side effects and others may occur. A healthcare provider can advise you on side effects. If you experience other effects, contact your pharmacist or a healthcare provider. You may report side effects to the Food and Drug Administration ( FDA) at fda.gov/medwatch or 800-FDA-1088.

Common Side Effects

EpiPen can cause some side effects such as:

  • Breathing problems
  • Dizziness
  • Headache
  • Feeling restless, fearful, nervous, anxious, or excited
  • Nausea and vomiting
  • Pale skin
  • Sweating
  • Tremors or uncontrollable shaking of body parts
  • Weakness

Severe Side Effects

Seek medical help after injecting epinephrine. Tell your healthcare provider if you have:

  • Skin redness, swelling or tenderness at the site of injection
  • Difficulty breathing
  • Pounding, fast, or irregular heartbeat

Contact your healthcare provider right away if you develop any signs of a severe reaction. Call 911 if your symptoms feel life-threatening.

Long-Term Side Effects

Information about long-term side effects of Epipen use is lacking.

Report Side Effects

EpiPen may cause other side effects. Call your healthcare provider if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your provider may send a report to the FDA's MedWatch Adverse Event Reporting Program or by phone (800-332-1088).

Dosage: How Much EpiPen Should I Take?

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The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For injection dosage form (solution):
    • For allergic reactions:
      • Adrenaclick®, Auvi-q®, Epipen®, Epipen Jr®, Twinject®:
        • Adults and children weighing 30 kilograms (kg) or more—0.3 milligram (mg) injected under the skin or into the muscle of your thigh.
        • Children weighing 15 to 30 kg—0.15 mg injected under the skin or into the muscle of your thigh.
        • Children weighing 7.5 to 15 kg—0.1 mg injected under the skin or into the muscle of your thigh.
        • Children weighing less than 7.5 kg—Use and dose must be determined by your doctor.
      • Adrenalin®:
        • Adults and children weighing 30 kilograms (kg) or more—0.3 to 0.5 milligram (mg) injected under the skin or into the muscle of your thigh. You may repeat the injection every 5 to 10 minutes as needed.
        • Children weighing less than 30 kg—Dose is based on body weight and must be determined by your doctor. The dose is 0.01 mg per kg of body weight injected under the skin or into the muscle of your thigh. You may repeat the injection every 5 to 10 minutes as needed. However, the dose is usually not more than 0.3 mg per injection.
      • Symjepi™:
        • Adults and children weighing 30 kilograms (kg) or more—0.3 milligrams (mg) injected under the skin or into the muscle of your thigh.
        • Children weighing 15 to 30 kg—0.15 mg injected under the skin or into the muscle of your thigh.
        • Children weighing less than 15 kg—Use and dose must be determined by your doctor.

Modifications

The following modifications (changes) should be kept in mind when using EpiPen:

Children: When used in children, the dose should be adjusted according to the child’s body weight.

Pregnancy or breastfeeding: EpiPen should only be used in people who are pregnant or breastfeeding if the benefits outweigh the risks.

People over the age of 65 years: EpiPen should be administered with caution in people over the age of 65 years as, depending on various factors, they might be at greater risk of experiencing side effects. 

Heart conditions: Epinephrine should be used with caution in people with heart conditions, such as arrhythmia, coronary artery disease, heart disease, or high blood pressure. For people with these conditions, or in people who take certain medications (including anti-arrhythmia drugs, digitalis, and diuretics), epinephrine may cause or worsen angina pectoris or produce ventricular arrhythmias.

However, it's important to note that in an acute, life-threatening allergic reaction, it's still suggested to use the EpiPen—even if you have these conditions.

Be sure to speak with your healthcare provider about any questions or concerns that you may have.

Missed Dose

EpiPen is normally used under emergency conditions only. Therefore, epinephrine does not have a daily dosing schedule.

Overdose: What Happens If I Take Too Much EpiPen?

Symptoms of an epinephrine overdose may include:

  • Irregular heartbeat
  • Fainting
  • Change in vision
  • Confusion
  • Seizures

If you think that you're experiencing an overdose or life-threatening symptoms, however, seek immediate medical attention.

What Happens If I Overdose Using the EpiPen?

If you think you or someone else may have overdosed on epinephrine call a healthcare provider or the Poison Control Center (800-222-1222).

If someone collapses or isn't breathing after using the EpiPen, call 911 immediately.

Precautions

Drug Content Provided and Reviewed by IBM Micromedex®

Anaphylaxis is a life-threatening reaction and requires immediate medical attention. Check with your doctor right away, or go to an emergency room as soon as possible, even if you feel better after using this medicine.

Tell your doctor if you develop symptoms of an infection (eg, redness that does not go away, swelling, warmth, or tenderness) at the injection site.

This medicine may affect blood sugar levels. If you notice a change in the results of your blood or urine sugar tests or if you have any questions, check with your doctor.

Do not inject this medicine into your buttocks. Epinephrine may not work as well and may cause gas gangrene. Check with your doctor or go to the hospital emergency room right away to get additional treatment.

Do not inject this medicine into your hands or feet. There is already less blood flow to the hands and feet, and epinephrine could make that worse and cause damage to these tissues. If you accidentally inject epinephrine into your hands or feet, check with your doctor or go to the hospital emergency room right away.

This medicine may worsen the condition of patients with heart disease or heart rhythm problems. Check with your doctor right away if you have chest pain or tightness, decreased urine output, dilated neck veins, extreme fatigue, irregular heartbeat, swelling of the face, fingers, feet, or lower legs, trouble breathing, or weight gain. You might also feel dizzy or faint, or you might have a fast, pounding, or uneven heartbeat.

This medicine may cause pulmonary edema (fluid in the lungs). Check with your doctor right away if you have chest pain, difficult, fast, or noisy breathing, blue lips and fingernails, pale skin, increased sweating, coughing that sometimes produces a pink frothy sputum, or swelling in the legs and ankles.

Check with your doctor right away if you have bloody urine, a decrease in frequency or amount of urine, an increase in blood pressure, increased thirst, loss of appetite, lower back or side pain, nausea, swelling of the face, fingers, or lower legs, trouble breathing, unusual tiredness or weakness, vomiting, or weight gain. These could be symptoms of a serious kidney problem.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

What Are Reasons I Shouldn’t Take EpiPen?

Epinephrine should be used with caution in people with heart conditions. This includes arrhythmia, coronary artery disease, heart disease, or high blood pressure.

For people with these conditions, or in people who take certain medications, such as anti-arrhythmia drugs, digitalis, and diuretics, epinephrine may cause or worsen certain heart conditions, including angina pectoris, or produce ventricular arrhythmias.

However, it's important to note that in an acute, life-threatening allergic reaction, it's still suggested to use EpiPen—even if you have these conditions.

What Other Medications Interact With EpiPen?

Use caution when taking EpiPen with the following medications:

Epinephrine may interact with certain drugs that include:


Antidepressants such as:

  • Anafranil (clomipramine)
  • Asendin (amoxapine)
  • Elavil (amitriptyline)
  • Norpramin (desipramine)
  • Pamelor (nortriptyline)
  • Remeron (mirtazapine) 
  • Silenor (doxepin)
  • Surmontil (trimipramine)
  • Tofranil (imipramine)
  • Vivactil (protriptyline) 

Antihistamines such as:

  • Chlor-Trimeton (chlorpheniramine) 
  • Benadryl (diphenhydramine)

Beta-blockers such as:

  • Inderal (Propranolol)


Monoamine oxidase inhibitors (MAOIs) such as:

  • Marplan (Isocarboxazid)
  • Nardil (phenelzine)
  • Parnate (tranylcypromine)


Others:

  • Lanoxin (digoxin)
  • Diuretics (water pills, which rid the body of salt and water)
  • Ergot medications such as Ergomar (ergotamine) 
  • Levoxyl (levothyroxine)
  • Medications for irregular heartbeat like quinidine
  • Regitine (phentolamine)

For more detailed information about medication interactions with EpiPen, talk with your pharmacist or healthcare provider.

And be sure to talk with your healthcare provider about all prescription and nonprescription medications, vitamins, supplements, and herbal products you are taking or plan to take.

What Medications Are Similar?

Alternative auto-injectors to EpiPen include:

Generic epinephrine auto-injectors include:

  • Authorized generic for EpiPen and EpiPen Jr
  • Epinephrine
  • Authorized generic for Adrenaclick

Frequently Asked Questions

  • What is the EpiPen used for?

    EpiPen treats allergic reactions caused by medications, foods, insect bites or stings, and latex, as well as other causes. It's also used to treat certain heart problems. Epinephrine is sometimes added to anesthesia to make the anesthetics last longer.

  • How does the EpiPen work?

    EpiPen is an auto-injector device that releases epinephrine into the body. Epinephrine works by relaxing your airway muscles and tightening your blood vessels. It reverses the effect of anaphylaxis (severe allergic reaction).

  • What drugs should not be taken with Epinephrine?

    Some drugs that interact with epinephrine are:

    • Asthma medicines
    • Antidepressants
    • Cold or allergy medicine
    • Heart and blood pressure medicine
    • Thyroid medication
    • Ergot medicines

How Can I Stay Healthy While Using EpiPen?

Anaphylactic shock, or a severe allergic reaction, can be life-threatening. Work with your healthcare providers to understand your triggers. It’s important to inject epinephrine when you have severe allergy symptoms. People with a known history of hypersensitivity must keep this device with them at all times.

It’s important to note that injecting epinephrine only provides temporary relief. You should seek medical help after injecting EpiPen as you may need a second dose or other emergency medical treatments. Also consider the following:

  • Take allergy-related medications as recommended by your healthcare provider.
  • Consider keeping a diary to become more aware of your allergy triggers.
  • Always have your EpiPen with you.
  • Do your best to avoid your allergy triggers.
  • Consider joining a support group or working with a mental health professional to help you find coping strategies to change the way you think, feel, react, or respond to living with severe allergies.

Medical Disclaimer

Verywell Health's drug information is meant for educational purposes only and is not intended as a replacement for medical advice, diagnosis, or treatment from a healthcare provider. Consult your healthcare provider before taking any new medication(s). IBM Watson Micromedex provides some of the drug content, as indicated on the page.

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