EPINEPHRINE USES WITH DOSE
Epinephrine is the first-line, life-saving medication for anaphylaxis (0.2-0.5 mg IM every 5-15 minutes), cardiac arrest (1 mg IV every 3-5 minutes), and serves as adjunctive therapy for severe bronchospasm and refractory hypotension when standard treatments fail.
Anaphylaxis
Administer 0.2-0.5 mg (0.01 mg/kg in children, max 0.3 mg) of 1:1000 epinephrine intramuscularly into the anterolateral thigh immediately upon recognition of systemic allergic reaction, especially with hypotension, airway swelling, or difficulty breathing 1. Repeat every 5-15 minutes as needed—many patients require multiple doses 1.
Route Selection for Anaphylaxis:
- Intramuscular (preferred): Fastest absorption, safest profile, produces rapid peak plasma concentrations when injected into lateral thigh 1
- Intravenous (alternative): When IV access already established in anaphylactic shock, use 0.05-0.1 mg (1:10,000 dilution) as slow bolus 1
- IV infusion: Reasonable alternative for refractory cases—prepare 1 mg in 250 mL D5W (4 mcg/mL), infuse at 1-4 mcg/min, titrate up to 10 mcg/min 2. Alternative: 5-15 mcg/min infusion 1
Critical pitfall: IV epinephrine carries significant risk of lethal arrhythmias, hypertension, and coronary vasospasm 2. Reserve for profoundly hypotensive patients who fail IM epinephrine and volume resuscitation. Continuous hemodynamic monitoring is essential 2.
Cardiac Arrest
Administer 1 mg IV/IO every 3-5 minutes during resuscitation 3. This is a Class I recommendation with moderate-quality evidence showing improved return of spontaneous circulation (ROSC) and short-term survival 3.
Timing Considerations:
- Non-shockable rhythms (asystole, PEA): Give epinephrine as soon as feasible 3
- Shockable rhythms (VF, pulseless VT): May give after initial defibrillation attempts fail 3
- Anaphylaxis-induced arrest: Standard resuscitative measures with immediate epinephrine administration take priority 1
High-dose epinephrine (>1 mg) is NOT recommended—offers no benefit and may cause harm 3.
Cardiac Arrest from Anaphylaxis:
Use high-dose IV epinephrine with rapid escalation: 1-3 mg (1:10,000) IV over 3 minutes, then 3-5 mg over 3 minutes, followed by 4-10 mg/min infusion 2. Prolonged resuscitation efforts are encouraged as these patients are often young with healthy cardiovascular systems 2.
Severe Bronchospasm
For bronchospasm resistant to adequate epinephrine doses: Consider nebulized albuterol 2.5-5 mg in 3 mL saline, repeated as necessary 2.
Refractory post-intubation bronchospasm: As last resort, 0.5 mg epinephrine (1:10,000) in 10 mL normal saline via endotracheal tube has shown benefit 4, though this is off-guideline use based on case reports.
Refractory Hypotension
For hypotension unresponsive to volume replacement and epinephrine injections: Initiate vasopressor infusion with continuous hemodynamic monitoring 2.
Dopamine Protocol:
- Prepare 400 mg in 500 mL D5W
- Infuse at 2-20 mcg/kg/min
- Titrate to maintain systolic BP >90 mmHg 2
Post-Arrest Hypotension:
Consider bolus epinephrine (dose not standardized but case reports suggest 10-100 mcg IV boluses) for immediate effect while preparing infusion 5. IV epinephrine infusion (5-15 mcg/min) may be considered for post-arrest shock in anaphylaxis 1.
Vasoconstrictor Adjunct to Local Anesthesia
The provided evidence does not address epinephrine use with local anesthetics. This indication requires separate FDA labeling review.
Special Populations & Contraindications
There is NO absolute contraindication to epinephrine in anaphylaxis 2, 6. The therapeutic benefits exceed risks when given in appropriate IM doses 7.
High-Risk Patients Requiring Caution:
- Beta-blocker therapy: Consider glucagon 1-5 mg IV over 5 minutes, followed by 5-15 mcg/min infusion, as beta-blockade may blunt epinephrine response 2
- Elderly patients: May be particularly sensitive; consider lower initial doses for anaphylaxis 6
- Pregnancy: Category C—use only if benefit justifies fetal risk (potential for fetal anoxia, uterine vasoconstriction) 6
- Cardiovascular disease: May aggravate angina or produce arrhythmias, but withholding epinephrine in anaphylaxis is more dangerous 6
Pediatric Dosing:
- Anaphylaxis: 0.01 mg/kg IM (max 0.3 mg) of 1:1000 solution 1, 2, 6
- Cardiac arrest: 0.01 mg/kg IV (0.1 mL/kg of 1:10,000 solution, max 0.3 mg) every 3-5 minutes 2
- Autoinjectors: 0.15 mg for children <30 kg, 0.3 mg for ≥30 kg 1
Key Clinical Pearls
- Epinephrine is dramatically underutilized in anaphylaxis despite being the only first-line treatment 7, 8
- Never inject into buttocks, digits, hands, or feet—risk of tissue necrosis 6
- Sulfite preservative should not deter use in anaphylaxis 6
- Close monitoring mandatory: Cardiovascular and respiratory status can deteriorate rapidly in anaphylactic shock 1
- Delayed deterioration occurs in 17% of anaphylaxis cases, often within 4 hours—adequate initial epinephrine dosing may reduce this risk 9
- All at-risk patients should carry two epinephrine autoinjectors and demonstrate proper technique 8