Adult Epinephrine Dosing
For anaphylaxis, give 0.3-0.5 mg (1:1000) intramuscularly into the anterolateral thigh, repeated every 5-15 minutes as needed; for cardiac arrest, follow standard ACLS with 1 mg IV/IO every 3-5 minutes. 1
Anaphylaxis Dosing (Without Cardiac Arrest)
The 2020 AHA Guidelines provide clear, evidence-based recommendations for epinephrine in anaphylaxis 1:
Intramuscular Route (First-Line)
- Dose: 0.2-0.5 mg of 1:1000 (1 mg/mL) solution
- Route: Intramuscular injection into the anterolateral thigh
- Frequency: Repeat every 5-15 minutes as needed
- Autoinjector: Delivers 0.3 mg per dose 1
This is a Class I recommendation - epinephrine should be administered early to all patients with signs of systemic allergic reaction, especially hypotension, airway swelling, or difficulty breathing 1. The intramuscular route is preferred because it produces rapid peak plasma concentrations, is safe, and is easy to administer 1, 2.
Intravenous Route (Alternative for Shock)
When IV access is already established in anaphylactic shock:
- Dose: 0.05-0.1 mg (50-100 mcg) of 1:10,000 solution
- Note: This is only 5-10% of the standard cardiac arrest dose 1
- Infusion option: 5-15 mcg/min for refractory or recurrent shock 1
Critical caveat: IV epinephrine carries significantly higher risk of adverse effects (arrhythmias, hypertension) and should only be used when IV access is already in place and the patient is in shock 3. The much lower dose compared to cardiac arrest dosing reflects this risk.
Cardiac Arrest Dosing
Standard ACLS Protocol
For cardiac arrest from any cause, including anaphylaxis 1, 4:
- Dose: 1 mg IV/IO
- Concentration: 1:10,000 (0.1 mg/mL)
- Frequency: Every 3-5 minutes during resuscitation
- Timing in shockable rhythms: Administer after initial CPR and defibrillation attempts are unsuccessful 4
The 2025 AHA Guidelines reaffirm this approach 4, noting that while epinephrine improves return of spontaneous circulation (ROSC) and survival to hospital admission, evidence for improved neurologic outcomes remains limited. However, epinephrine remains the standard of care as ROSC is a prerequisite for any meaningful recovery.
Cardiac Arrest from Anaphylaxis
The approach is identical to standard ACLS 1:
- Use standard resuscitative measures
- Administer epinephrine 1 mg IV/IO immediately
- Continue standard dosing every 3-5 minutes
- No proven benefit from antihistamines, beta-agonists, or corticosteroids during the arrest itself 1
Key Clinical Distinctions
The dosing differs dramatically based on clinical scenario:
| Scenario | Dose | Route | Concentration |
|---|---|---|---|
| Anaphylaxis (no arrest) | 0.3-0.5 mg | IM (thigh) | 1:1000 |
| Anaphylactic shock (IV available) | 0.05-0.1 mg | IV bolus | 1:10,000 |
| Any cardiac arrest | 1 mg | IV/IO | 1:10,000 |
The 10-fold difference between anaphylaxis IM dosing (using 1:1000) and cardiac arrest IV dosing (using 1:10,000) reflects both the different concentrations and the different clinical contexts 1, 5.
Common Pitfalls to Avoid
Wrong concentration: Using 1:1000 IV instead of 1:10,000 can deliver 10 times the intended dose and cause severe complications 3
Delayed administration in anaphylaxis: Failure to inject epinephrine promptly contributes to anaphylaxis fatalities 2. Give it immediately when indicated.
Wrong site for IM injection: Never inject into buttocks, digits, hands, or feet 5. The anterolateral thigh provides optimal absorption.
Withholding epinephrine due to comorbidities: There is no absolute contraindication to epinephrine in anaphylaxis, even in elderly patients or those with cardiac disease 6. The risk of untreated anaphylaxis exceeds the risk of epinephrine.
Prioritizing epinephrine over defibrillation: In shockable cardiac arrest rhythms, prioritize rapid defibrillation first; give epinephrine after initial attempts with CPR and defibrillation are unsuccessful 4.
Post-Resuscitation Considerations
For patients with return of spontaneous circulation after anaphylaxis-induced arrest, consider epinephrine infusion for persistent shock 1:
- Dose: 5-15 mcg/min IV
- Titrate based on blood pressure and clinical response
- Allows careful dose adjustment and avoids bolus-related complications 1