Reviewed on 8/4/2022

What Is Epinephrine and How Does It Work?

Epinephrine is a prescription medication used to treat severe allergic reactions (anaphylaxis) to insect stings or bites, foods, drugs, and other allergens.

  • Epinephrine is available under various brand names: Adrenalin

What Are Side Effects Associated with Using Epinephrine?

Common side effects of Epinephrine include:

  • breathing problems.
  • fast or pounding heartbeats.
  • pale skin, sweating.
  • nausea and vomiting.
  • dizziness.
  • weakness or tremors.
  • throbbing headache; or
  • feeling nervous, anxious, or fearful.

Serious side effects of Epinephrine include:

  • hives.
  • difficult breathing;
  • swelling of your face, lips, tongue, or throat.

Rare side effects of Epinephrine include:

  • none

Seek medical care or call 911 at once if you have the following serious side effects:

  • Severe headache, confusion, slurred speech, arm or leg weakness, trouble walking, loss of coordination, feeling unsteady, very stiff muscles, high fever, profuse sweating, or tremors;
  • Serious eye symptoms such as sudden vision loss, blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights;
  • Serious heart symptoms such as fast, irregular, or pounding heartbeats; fluttering in the chest; shortness of breath; sudden dizziness, lightheartedness, or passing out.

This is not a complete list of side effects and other serious side effects or health problems that may occur because of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.

What are Dosages of Epinephrine?

Adult and pediatric dosage

prefilled autoinjector or syringe for SC/IM use

  • 0.1 mg/0.1mL (Audi-Q)
  • 0.15 mg/0.15mL (EpiPen Jr, Auvi-Q, Symjepi)
  • 0.3 mg/0.3mL (EpiPen, Auvi-Q, Symjepi)
  • injectable solution
  • 0.1 mg/mL (1mg/10mL)
  • 1 mg/mL

Cardiac Arrest

Adult dosage

  • Intravenous
    • Recommended dose: 0.5-1.0 mg (5-10 mL)
    • During a resuscitation effort, 0.5 mg (5 mL) intravenous every 5min
  • Intracardiac
    • Intracardiac injection if there has not been sufficient time to establish an Intravenous route
    • Usual dose ranges from 0.3-0.5 mg (3-5 mL)
  • Endotracheal tube
    • Alternatively, if the patient has been intubated, epinephrine can be injected via the endotracheal tube directly into the bronchial tree at the same dosage as for IV injection
    • 2-2.5 mg every 3-5min until Intravenous/IO access is established or spontaneous circulation restored

Hypotension associated with Septic Shock

Adult dosage

  • Indicated to increase mean arterial blood pressure in adults with hypotension associated with septic shock
  • Recommended dose: 0.05-2 mcg/kg/minute Intravenous infusion; titrate to desired mean arterial pressure (MAP); may adjust dose every 10-15 min by 0.05-0.2 mcg/kg/minute to achieve desired blood pressure goal
  • After hemodynamic stabilization, may wean incrementally every 30 min over 12-24 hours
  • See also Administration


  • Adult dosage
  • Indicated in the emergency treatment of allergic reactions (Type I) including anaphylaxis
  • 0.1 mg/mL solution
  • 0.1 mg IV at a rate of 1-4 mcg/min over 5 min to prevent the need to repeat injections frequently OR may initiate with an infusion at 5-15 mcg/min (with crystalloid administration); IV administration should only be done in patients who are profoundly hypotensive or are in cardiopulmonary arrest refractory to volume resuscitation and several epinephrine injections
  • 1 mg/mL solution
  • 0.3-0.5 mg (0.3-0.5 mL) of undiluted epinephrine IM/SC once in the anterolateral aspect of the thigh, not to exceed 0.5 mg (0.5 mL) per injection, repeated every 5-10 minutes as necessary
  • Monitor clinically for reaction severity and cardiac effects
  • Prefilled autoinjector or syringe
  • 0.3 mg (contents of 1 autoinjector) SC/IM once in the anterolateral aspect of the thigh; may repeat dose after 5-15 minutes if symptoms persist

Pediatric dosage

  • Indicated in the emergency treatment of allergic reactions (Type I) including anaphylaxis
  • 1mg/mL solution
    • Children below 30 kg (66 lbs): 0.01 mg/kg (0.01 mL/kg) Subcutaneous/Intramuscular, not to exceed 0.3 mg (0.3 mL) per injection, repeated every 5-10 min as necessary  
    • Children above30 kg (66 lbs): 0.3-0.5 mg (0.3-0.5 mL) Subcutaneous/Intramuscular, not to exceed 0.5 mg (0.5 mL) per injection, repeated every 5-10 min as necessary
  • Autoinjector
    • May repeat dose after 5-15 minutes if symptoms persist
    • Infants weighing 7.5-15 kg (16.5-33 lb); Audi-Q only: 0.1 mg SC/IM once
    • Weight 15 to above 30 kg: 0.15 mg (contents of 1 autoinjector/prefilled syringe) SC/IM once; may repeat dose q5-15min
    • Weight above 30 kg: 0.3 mg (contents of 1 autoinjector/prefilled syringe) SC/IM once; may repeat dose evey5-15min

Symptomatic Bradycardia

Adult dosage

  • Unresponsive to atropine or pacing: 2-10 mcg//min by Intravenous infusion or 0.1-0.5 mcg/kg/min(7-35 mcg/min in 70 kg patient); titrate to patient response
  • Mydriasis

Adult dosage

  • Induction and maintenance of mydriasis during intraocular surgery
  • Use only preservative-free vials without tartaric acid
  • Intraocular irrigating solution
  • Dilute 1 mg (of 1 mg/mL single-use solution) to 1-10 mcg/mL
  • Use as needed during the procedure
  • Intraocular intracameral injection
  • Dilute 1 mg (of 1 mg/mL single-use solution) to 2.5-10 mcg/mL
  • Injection volume: 0.1 mL

Dosage Considerations – Should be Given as Follows: 

  • See “Dosages”

What other drugs interact with Epinephrine?

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them.  Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drug interactions. Therefore, before using this product, tell your doctor or pharmacist about all your products. Keep a list of all your medications with you and share this information with your doctor and pharmacist. Check with your health care professional or doctor for additional medical advice, or if you have health questions or concerns.

What are warnings and precautions for Epinephrine?


  • None

Effects of drug abuse

  • None

Short-Term Effects

  • See “What Are Side Effects Associated with Using Epinephrine?”

Long-Term Effects

  • See “What Are Side Effects Associated with Using Epinephrine?”


  • Serious postpartum hypertension and stroke reported with coadministration of a vasopressor (ie, methoxamine, phenylephrine, ephedrine) and an oxytocic (ie, methylergonovine, ergonovine); monitor BP if the patient has received both ephedrine and an oxytocic
  • Repeated administration may cause tachyphylaxis; an alternative vasopressor may be needed to mitigate unresponsiveness to treatment
  • An increased incidence of hypertension has occurred when used for prevention compared with the treatment of hypotension

Drug interaction overview

  • Oxytocin and oxytocic drugs
    • Carefully monitor BP
    • Coadministration of a vasopressor and an oxytocic cause serious postpartum hypertension; some patients experienced a stroke
  • Drugs that augment vasopressor effects of ephedrine
    • Carefully monitor BP
    • Clonidine, propofol, monoamine oxidase inhibitors (MAOIs), atropine may augment the vasopressor effects of ephedrine
  • Drugs that antagonize vasopressor effects of ephedrine
    • Carefully monitor BP
    • Alpha-adrenergic antagonists, beta-adrenergic receptor antagonists, reserpine, or quinidine may antagonize the vasopressor effects of ephedrine
  • Rocuronium
    • Be aware of the interaction
    • Ephedrine may reduce the onset time of neuromuscular blockade when used for intubation with rocuronium if administered simultaneously with anesthetic induction
  • Epidural anesthesia
    • Monitor and treat according to clinical practice
    • Ephedrine may decrease the efficacy of epidural blockage by hastening the regression of sensory analgesia
  • Theophylline
    • Monitor for worsening symptoms and manage symptoms according to clinical practice
    • Ephedrine may increase the frequency of nausea, nervousness, and insomnia
  • Cardiac glycosides
    • Carefully monitor
    • Coadministration with a cardiac glycoside (eg, digoxin) may increase the risk of arrhythmias

Pregnancy and Lactation

  • Available data of use in pregnant females have not identified a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes
  • Untreated hypotension associated with spinal anesthesia for cesarean section is associated with an increase in maternal nausea and vomiting
  • Decreased uterine blood flow due to maternal hypotension may result in fetal bradycardia and acidosis
  • Fetal/neonatal adverse reactions
    • Cases of potential metabolic acidosis in newborns at delivery with maternal ephedrine exposure have been reported in the literature
    • These reports describe umbilical artery pH of less than or 7.2 at the time of delivery
    • Monitor newborn for signs and symptoms of metabolic acidosis
  • A single published case report indicates that ephedrine is present in human milk
  • No information is available on its effects on breastfed infants or milk production
Medscape. Epinephrine.



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