Symjepi (epinephrine)

Generic drug: epinephrine

Brand name: Symjepi

What is Symjepi (epinephrine), and how does it work?

  • Symjepi (epinephrine) is a disposable, prefilled syringe used to treat life-threatening, allergic emergencies including anaphylaxis in people who are at risk for or have a history of serious allergic emergencies. Each prefilled syringe contains a single (1 time) dose of epinephrine.
  • Symjepi is for immediate self (or caregiver) administration and does not take the place of emergency medical care. You should get emergency help right away after using Symjepi.
  • Symjepi is for people who have been prescribed this medicine by their healthcare provider.
  • The Symjepi 0.3 mg prefilled syringe is for patients who weigh 66 pounds or more (30 kilograms or more).
  • The Symjepi 0.15 mg prefilled syringe is for patients who weigh between 33 and 66 pounds (15 to 30 kilograms or more).
  • It is not known if the Symjepi prefilled syringe is safe and effective in patients who weigh less than 33 pounds (15 kilograms).

What are the side effects of Symjepi?

Symjepi may cause serious side effects.

  • Symjepi should only be injected into the middle of your outer thigh (upper leg). Do not inject Symjepi into your:
    • veins
    • buttocks
    • fingers, toes, hands, or feet

If you accidentally inject Symjepi into any other part of your body, go to the nearest emergency room right away. Tell the healthcare provider where on your body you received the accidental injection.

  • Rarely, patients who have used Symjepi may develop infections at the injection site within a few days of an injection. Some of these infections can be serious. Call your healthcare provider right away if you have any of the following at an injection site:
    • redness that does not go away
    • swelling
    • tenderness
    • the area feels warm to the touch
  • Cuts on the skin, bent needles, and needles that remain in the skin after the injection, have happened in young children who do not cooperate and kick or move during an injection. If you inject a young child with Symjepi, hold their leg firmly in place before and during the injection to prevent injuries. Ask your healthcare provider to show you how to properly hold the leg of a young child during injection.
  • If you have certain medical conditions, or take certain medicines, your condition may get worse or you may have longer lasting side effects when you use your Symjepi. Talk to your healthcare provider about all your medical conditions.

Common side effects of Symjepi include:

These side effects may go away with rest. Tell your healthcare provider if you have any side effect that bothers you or that does not go away.

These are not all the possible side effects of Symjepi. For more information, ask your healthcare provider or pharmacist.

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What is the dosage for Symjepi?

Recommended Dosage According To Patient Body Weight

  • Patients greater than or equal to 30 kg (approximately 66 pounds or more):0.3 mg
  • Patients 15 kg to 30 kg (33 pounds to 66 pounds): 0.15 mg

Administration Instructions

  • Inject the single-dose Symjepi intramuscularly or subcutaneously into the anterolateral aspect of the thigh with the needle facing downwards. It can be injected through clothing if necessary. Do not inject intravenously, and do not inject into buttocks, into digits, hands and feet.
  • Instruct caregivers of young children who are prescribed Symjepi and who may be uncooperative and kick or move during an injection to hold the leg firmly in place and limit movement prior to and during an injection.
  • Each Symjepi is a single dose of epinephrine injection for single use. Since the doses of epinephrine delivered from Symjepi are fixed, consider using other forms of injectable epinephrine if doses lower than 0.15 mg are deemed necessary.
  • With severe persistent anaphylaxis, repeat injections with an additional Symjepi may be necessary. More than two sequential doses of epinephrine should only be administered under direct medical supervision.
  • Ensure that the patient or caregiver is instructed and understands the indications and use of this product. A health care provider should review the patient instructions for Symjepi, in detail, with the patient or caregiver. Patients and/or any other person who might be in a position to administer an epinephrine injection should be advised of the proper site for injection and given appropriate instructions about imbedding the needle before transferring the thumb to the syringe plunger.
  • The epinephrine solution in the syringe should be inspected visually for particulate matter and discoloration.

What drugs interact with Symjepi?

Cardiac Glycosides, Diurectics, And Anti-Arrhythmics

  • Patients who receive epinephrine while concomitantly taking cardiac glycosides, diuretics or anti-arrhythmics should be observed carefully for the development of cardiac arrhythmias.

Antidepressants, Monoamine Oxidase Inhibitors, Levothyroxine, And Antihistamines

Beta-Adrenergic Blockers

  • The cardiostimulating and bronchodilating effects of epinephrine are antagonized by beta-adrenergic blocking drugs, such as propranolol.

Alpha-Adrenergic Blockers

  • The vasoconstricting and hypertensive effects of epinephrine are antagonized by alpha-adrenergic blocking drugs, such as phentolamine.

Ergot Alkaloids

  • Ergot alkaloids may also reverse the pressor effects of epinephrine.


Common Allergies: Symptoms and Signs See Slideshow

Is Symjepi safe to use while pregnant or breastfeeding?

  • There are no adequate and well controlled studies of the acute effect of epinephrine in pregnant women.
  • Epinephrine is the first-line medication of choice for the treatment of anaphylaxis during pregnancy in humans.
  • Epinephrine should be used for treatment of anaphylaxis during pregnancy in the same manner as it is used in non-pregnant patients.
  • There is no information regarding the presence of epinephrine in human milk, the effects on breastfed infants, or the effects on milk production.
  • Epinephrine is the first line-medication of choice for treatment of anaphylaxis; it should be used in the same manner in breastfeeding and non-breastfeeding patients.


Symjepi (epinephrine) is a disposable, prefilled syringe used to treat life-threatening, allergic emergencies including anaphylaxis in people who are at risk for or have a history of serious allergic emergencies. Common side effects of Symjepi include fast, irregular or “pounding” heartbeat; sweating, headache, weakness, shakiness, paleness, feelings of over excitement, nervousness or anxiety, dizziness, nausea and vomiting, and breathing problems.

Treatment & Diagnosis

Prevention & Wellness

FDA Logo

Report Problems to the Food and Drug Administration

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

All sections courtesy of the U.S. Food and Drug Administration