What is the recommended initial dose of epinephrine (Epi) for anaphylaxis?

Recommended Initial Dose of Epinephrine for Anaphylaxis

The recommended initial dose of epinephrine for anaphylaxis is 0.2 to 0.5 mg (1:1000 concentration) intramuscularly into the anterolateral thigh, to be repeated every 5 to 15 minutes as needed. 1

Adult Dosing

• For adults and children weighing ≥30 kg (66 lbs):
  • 0.3 to 0.5 mg (0.3 to 0.5 mL of 1:1000 concentration) 1, 2
  • Maximum initial dose: 0.5 mg 1
  • Administered intramuscularly into the anterolateral thigh
  • May repeat every 5-15 minutes as needed based on clinical response 1

Pediatric Dosing

• For children weighing <30 kg (66 lbs):
  • 0.01 mg/kg (0.01 mL/kg of 1:1000 concentration) 1, 2
  • Maximum dose: 0.3 mg in prepubertal children 1
  • Administered intramuscularly into the anterolateral thigh
  • May repeat every 5-15 minutes as needed based on clinical response

Autoinjector Dosing Recommendations

When using epinephrine autoinjectors in community settings:

• 0.15 mg autoinjector: For children weighing 7.5-25 kg (16.5-55 lbs) 1
• 0.3 mg autoinjector: For individuals weighing ≥25 kg (55 lbs) 1
• 0.5 mg autoinjector: Consider for individuals weighing ≥45 kg based on shared decision-making 3

Route of Administration

• Preferred route: Intramuscular injection into the anterolateral thigh (vastus lateralis) 1

  • Achieves peak plasma concentrations promptly 1
  • More effective and safer than subcutaneous administration

• Alternative route (only when IV access is already established and in anaphylactic shock):

  • IV dose: 0.05 to 0.1 mg (5-10% of cardiac arrest dose) 1
  • Should only be considered in profound hypotension unresponsive to IM epinephrine and fluid resuscitation 1

Important Clinical Considerations

• Epinephrine is the cornerstone of anaphylaxis treatment and should be administered promptly 1

• Delayed administration is associated with poor outcomes, including fatality 1

• Antihistamines and bronchodilators are adjunctive treatments and should never replace epinephrine 1

• Common pitfalls:

  • Delayed administration due to uncertainty about diagnosis
  • Inappropriate route (subcutaneous instead of intramuscular)
  • Confusion between anaphylaxis dosing (1:1000) and cardiac arrest dosing (1:10,000) 4
  • Underdosing in larger patients when using standard autoinjectors 3

• For patients with refractory symptoms, consider:

  • Repeated IM doses of epinephrine every 5-15 minutes 1
  • IV fluid resuscitation with normal saline 1
  • Close hemodynamic monitoring 1

Epinephrine remains the most effective medication for anaphylaxis with its life-saving pharmacologic effects on multiple organ systems, preventing and relieving both upper and lower airway obstruction and shock 5. The intramuscular route in the anterolateral thigh provides the optimal therapeutic window with rapid onset of action and reduced risk of adverse effects compared to intravenous administration.