What is the initial dose of epinephrine (Epi) for an adult patient in cardiac arrest or anaphylactic emergency?

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Epinephrine Dosing for Adult Cardiac Arrest and Anaphylaxis

For adult cardiac arrest, administer 1 mg IV/IO every 3-5 minutes using 1:10,000 concentration (0.1 mg/mL); for anaphylaxis, give 0.3-0.5 mg IM into the lateral thigh using 1:1000 concentration (1 mg/mL), repeatable every 5-15 minutes. 1, 2, 3

Cardiac Arrest Dosing

Standard dose epinephrine is 1 mg IV/IO (1:10,000 concentration) administered every 3-5 minutes during ongoing resuscitation. 1, 3

  • This dosing improves return of spontaneous circulation (ROSC) compared to placebo, though evidence for improved survival to discharge or neurologically intact survival remains unclear. 3

  • Early administration within 1-3 minutes is associated with better outcomes for non-shockable rhythms (asystole/PEA). 3

  • High-dose epinephrine (0.1-0.2 mg/kg) does not improve survival or neurological outcomes compared to standard dosing and may worsen post-arrest outcomes despite potentially increasing ROSC rates. 3, 4

  • The 3-5 minute interval is based on expert consensus; research shows no significant outcome difference with intervals <3 minutes or >5 minutes. 5

Anaphylaxis Dosing

Intramuscular injection into the anterolateral thigh is the preferred first-line route, delivering 0.3-0.5 mg (using 1:1000 concentration) for adults. 1, 2, 3

  • The lateral thigh produces the most rapid peak plasma epinephrine concentrations compared to subcutaneous or deltoid injection. 1, 3

  • Repeat doses every 5-15 minutes as needed—many patients require multiple doses due to symptom recurrence. 1, 2, 3

  • Autoinjectors deliver 0.3 mg per dose for adults. 1

IV Epinephrine for Anaphylactic Shock

When IV access is already established or for refractory anaphylactic shock, use dramatically lower doses than cardiac arrest: 0.05-0.1 mg (50-100 mcg) as a slow IV bolus using 1:10,000 concentration. 1, 2, 3

  • This represents only 5-10% of the cardiac arrest dose. 1, 2

  • For persistent shock, initiate continuous IV infusion at 5-15 mcg/min, which allows careful titration and avoids epinephrine overdosing. 1, 2, 3

  • Close hemodynamic monitoring is mandatory due to rapid cardiovascular changes in anaphylactic shock. 1, 3

Critical Distinction to Prevent Fatal Errors

The concentration and route differ critically between indications: 1:1000 (1 mg/mL) IM for anaphylaxis versus 1:10,000 (0.1 mg/mL) IV for cardiac arrest. 2, 3

  • Administering the cardiac arrest dose IV to anaphylaxis patients causes severe systolic dysfunction and potentially lethal cardiac complications. 6

  • Hospitals should stock clearly labeled, pre-filled IM epinephrine syringes that are easily distinguished from IV formulations to prevent this iatrogenic error. 2, 6

  • The risk of error is amplified by the need for rapid decision-making in critically ill patients. 6

Special Scenario: Anaphylaxis Progressing to Cardiac Arrest

If anaphylaxis causes cardiac arrest, immediately switch to cardiac arrest dosing protocols (1 mg IV/IO every 3-5 minutes) with standard resuscitative measures taking priority. 1, 2

  • Standard cardiac arrest doses should be used rather than the lower anaphylaxis doses once arrest occurs. 1

  • Epinephrine remains the cornerstone of treatment and should be administered immediately. 1

Route-Specific Considerations

  • Intramuscular is preferred for anaphylaxis due to ease of administration, effectiveness, safety, and avoidance of severe hypertension and cardiac complications from IV overdose. 1, 3, 7

  • Intraosseous (IO) epinephrine is likely effective at comparable doses to IV, though not specifically studied in anaphylaxis. 1

  • If IV extravasation occurs, infiltrate the site with phentolamine to prevent tissue necrosis. 2, 3

Patients on Beta-Blockers

Patients taking beta-blockers may have refractory hypotension despite epinephrine and may require glucagon 1-5 mg IV over 5 minutes followed by infusion at 5-15 mcg/min. 3

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Guideline

Pediatric Adrenaline Dosing Guidelines

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Guideline

Epinephrine Dosing Guidelines

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Research

Epinephrine (adrenaline) in anaphylaxis.

Chemical immunology and allergy, 2010

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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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