What is Epinephrine (Epi)?

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Last updated: March 27, 2025View editorial policy

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From the Guidelines

Epinephrine is a life-saving medication used to treat severe allergic reactions, cardiac arrest, and certain types of shock, and its administration is crucial in emergency situations to prevent morbidity, mortality, and improve quality of life.

Definition and Use

Epinephrine, also known as adrenaline, is a hormone and medication that plays a critical role in treating anaphylaxis, a severe, potentially fatal systemic allergic reaction. According to the most recent and highest quality study 1, epinephrine is the primary medical therapy for anaphylaxis and must be administered promptly. The recommended dose is 0.01 mg/kg of 1 mg/mL (1:1000), up to 0.5 mg in adults and 0.3 mg in children and teenagers, administered intramuscularly into the vastus lateralis (antero-lateral thigh).

Administration and Dosage

The administration of epinephrine is critical in emergency situations, and the dosage should be adjusted according to the patient's weight and the severity of the reaction. As stated in the study 1, there are no absolute contraindications to the use of epinephrine for anaphylaxis, and additional doses of intramuscular epinephrine should be given every 5 to 15 minutes if anaphylaxis signs or symptoms persist.

Importance of Prompt Administration

Delayed use of epinephrine can be ineffective, and fatal outcomes are often associated with delay or lack of administration of epinephrine, as reported in the study 1. Therefore, it is essential to administer epinephrine promptly in emergency situations to prevent morbidity, mortality, and improve quality of life.

Education and Training

Patients and their caregivers should be educated about the signs and symptoms of anaphylaxis and trained on proper administration technique of epinephrine auto-injectors, such as EpiPen or Auvi-Q, as recommended in the study 1. This education and training are crucial in ensuring that patients receive timely and effective treatment in emergency situations.

Side Effects and Benefits

While epinephrine can cause side effects such as anxiety, tremors, palpitations, and increased blood pressure, these are generally outweighed by the life-saving benefits in emergency situations, as stated in the example answer. The benefits of epinephrine in treating anaphylaxis and other emergency situations far outweigh the potential risks, and its administration is critical in preventing morbidity, mortality, and improving quality of life.

From the FDA Drug Label

Epinephrine is a non-selective alpha- and beta-adrenergic agonist Epinephrine is a sympathomimetic catecholamine (adrenergic agent) Epinephrine is a sympathomimetic catecholamine

Epinephrine, also known as adrenaline, is a sympathomimetic catecholamine that acts as a non-selective alpha- and beta-adrenergic agonist. It is a medication used to increase mean arterial blood pressure in adult patients with hypotension associated with septic shock, among other uses. 2 2 3

From the Research

Definition and Role of Epinephrine

  • Epinephrine, also known as adrenaline, is a medication used to treat anaphylaxis, a severe and potentially life-threatening allergic reaction 4, 5, 6, 7, 8.
  • It is considered the first-line treatment for anaphylaxis and is typically administered intramuscularly in the anterolateral thigh 4, 5, 6, 7.

Administration and Dosage

  • The recommended adult dose of epinephrine is 0.3-0.5 mg, injected intramuscularly in the anterolateral aspect of the mid-thigh 5.
  • For children, the dose is 0.01 mg/kg, given in the lateral thigh 6.
  • Epinephrine autoinjectors are available in different doses, including 0.15 mg, 0.30 mg, and 0.50 mg, and are prescribed based on the patient's weight 7.

Importance of Prompt Administration

  • Delayed administration of epinephrine can be fatal, and it is essential to administer it immediately after the onset of anaphylaxis symptoms 4, 5, 6, 8.
  • Prompt administration of epinephrine can help prevent unnecessary increases in patient morbidity and mortality 4.

Comparison with Other Treatments

  • Antihistamines and corticosteroids are second-line medications and should not be given in lieu of, or prior to, epinephrine 4.
  • The use of antihistamines and corticosteroids in anaphylaxis management is still being studied, and their effectiveness is not as well-established as that of epinephrine 8.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Anaphylaxis.

The Journal of emergency medicine, 2014

Research

Epinephrine (adrenaline) in anaphylaxis.

Chemical immunology and allergy, 2010

Research

The role of epinephrine in the treatment of anaphylaxis.

Current allergy and asthma reports, 2003

Research

CSACI position statement: transition recommendations on existing epinephrine autoinjectors.

Allergy, asthma, and clinical immunology : official journal of the Canadian Society of Allergy and Clinical Immunology, 2021

Research

Managing anaphylaxis: Epinephrine, antihistamines, and corticosteroids: More than 10 years of Cross-Canada Anaphylaxis REgistry data.

Annals of allergy, asthma & immunology : official publication of the American College of Allergy, Asthma, & Immunology, 2023

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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