What is the recommended dose of epinephrine (EpiPen) for an adult?

Adult Epinephrine Dosing for Anaphylaxis

For adults, the recommended dose of epinephrine for anaphylaxis is 0.3 to 0.5 mg administered intramuscularly into the anterolateral thigh every 5-15 minutes as needed. 1

Proper Administration

• Route of administration: Intramuscular (IM) injection is strongly preferred over subcutaneous injection

  • The lateral thigh (vastus lateralis muscle) is the optimal injection site 2
  • IM injection provides more rapid absorption and higher plasma levels compared to subcutaneous or deltoid injections 2, 3

• Formulation: Use 1:1000 concentration (1 mg/mL) for IM injection 2

  • For adults weighing ≥30 kg (66 lbs), use 0.3-0.5 mg dose 2, 1
  • Auto-injectors (like EpiPen) deliver a fixed 0.3 mg dose for adults 2

Timing and Repeat Dosing

• Administer immediately upon recognition of anaphylaxis 4
• Approximately 10-20% of patients will require more than one dose 2
• Repeat doses can be given every 5-15 minutes if symptoms persist or recur 2
• Delayed administration is associated with increased morbidity and mortality 3

Special Considerations

Severe Cases Requiring IV Administration

For patients who don't respond to IM epinephrine and fluid resuscitation:

• IV epinephrine should be given at 0.05-0.1 mg (using 1:10,000 solution) 2
• Continuous hemodynamic monitoring is essential when using IV epinephrine 2
• IV infusion may be considered as an alternative to bolus dosing:
  • Prepare by adding 1 mg of epinephrine to 100 mL saline (1:100,000 solution)
  • Infuse at 5-15 μg/min and titrate based on response 2

Obese Patients

• Standard auto-injector needles may be too short to reach the muscle in obese adults 5
• In these cases, manual IM injection with an appropriate needle length may be necessary

Common Pitfalls to Avoid

1. Delayed administration - epinephrine should be the first medication given 3
2. Incorrect route - avoid subcutaneous injection when possible 2
3. Wrong injection site - thigh is superior to arm for IM injection 2, 3
4. Overreliance on antihistamines - these are second-line agents and do not replace epinephrine 2
5. Incorrect concentration - using 1:10,000 solution for IM injection can lead to overdose 2

Side Effects

Mild transient side effects are common and include:

• Anxiety, restlessness, tremor
• Dizziness, headache, palpitations
• Pallor and sweating 1

Serious adverse effects are rare with proper IM dosing but may include:

• Ventricular arrhythmias
• Sudden increases in blood pressure
• Myocardial ischemia 2, 1

There are no absolute contraindications to epinephrine use in anaphylaxis, even in patients with cardiovascular disease, as the benefits outweigh the risks 3.