What is the recommended intramuscular epinephrine dose in milliliters per kilogram for treating anaphylaxis in children and adults?

Epinephrine Dosing for Anaphylaxis

The recommended intramuscular epinephrine dose for anaphylaxis is 0.01 mg/kg of 1:1000 concentration (1 mg/mL), with a maximum of 0.5 mg for adults and 0.3 mg for children, administered into the anterolateral thigh. 1, 2

Weight-Based Dosing Algorithm

Adults and Children ≥30 kg (66 lbs)

• Administer 0.3 to 0.5 mg (0.3 to 0.5 mL) of 1:1000 epinephrine intramuscularly into the anterolateral thigh 2
• Maximum single dose is capped at 0.5 mg regardless of body weight, as higher doses increase cardiac adverse effects without improving outcomes 3

Children <30 kg (66 lbs)

• Administer 0.01 mg/kg (0.01 mL/kg) of 1:1000 epinephrine, up to a maximum of 0.3 mg (0.3 mL), intramuscularly into the anterolateral thigh 2
• This translates to 0.01 mL per kilogram when using the standard 1:1000 (1 mg/mL) concentration 1, 4

Autoinjector Dosing for Children

For children using epinephrine autoinjectors, the dosing is simplified by weight thresholds rather than precise calculations:

• Children 10-25 kg (22-55 lbs): Use 0.15 mg autoinjector (junior dose) 5, 1
• Children ≥25 kg (55 lbs): Switch to 0.3 mg autoinjector (adult dose) 5, 1

The American Academy of Pediatrics recommends switching at approximately 25 kg because at this weight, the 0.15 mg dose provides only 0.006 mg/kg (an underdose), while the 0.3 mg dose provides 0.012 mg/kg (a slight overdose but preferable during life-threatening anaphylaxis) 1

Special Considerations for High-Risk Children

• For children with asthma or other risk factors for fatal anaphylaxis, consider switching to the higher 0.3 mg dose at a lower weight than 25 kg 5, 1

Administration Technique

• Inject at a 90-degree angle perpendicular to the skin into the mid-outer aspect of the anterolateral thigh (vastus lateralis muscle) 1, 3
• The intramuscular route in the lateral thigh achieves peak plasma concentrations in 8±2 minutes, compared to 34±14 minutes with subcutaneous deltoid injection 1, 6
• The injection can be administered through clothing if necessary during emergencies, as delay increases mortality risk 1

Repeat Dosing Protocol

• Repeat every 5-15 minutes if symptoms persist, fail to resolve, or worsen 1, 4, 2
• Approximately 10-28% of patients require a second dose 3, 4
• There is no maximum number of doses—continue every 5 minutes as clinically needed until symptoms resolve 3, 4

Critical Pitfalls to Avoid

• Never delay epinephrine to give antihistamines or corticosteroids first—epinephrine is the only first-line treatment, and delays are associated with fatalities 1, 4, 7
• Avoid subcutaneous injection, which delays absorption significantly compared to intramuscular administration 1, 6
• Do not confuse concentrations: Always use 1:1000 (1 mg/mL) for intramuscular injection; 1:10,000 is reserved for intravenous use only 3, 8
• Avoid using ampule/syringe/needle methods for home use, as they carry a 40-fold variation in dosing accuracy and significant delays compared to autoinjectors 4

Intravenous Epinephrine (Reserved for Severe Cases Only)

IV epinephrine should only be used for cardiac arrest or profound hypotension unresponsive to multiple IM doses and aggressive fluid resuscitation 4:

• Initial infusion: 1-4 mcg/min, titrated up to maximum 10 mcg/min 1, 3
• Preparation: Add 1 mg (1 mL) of 1:1000 epinephrine to 250 mL D5W to yield 4 mcg/mL concentration 1, 3
• Requires continuous hemodynamic monitoring due to significant risk of cardiac complications 4, 8