What is the recommended dose of adrenaline (epinephrine) for treating anaphylaxis?

Adrenaline Dosing for Anaphylaxis

For anaphylaxis treatment, administer epinephrine (adrenaline) at a dose of 0.01 mg/kg (maximum 0.5 mg) intramuscularly in the anterolateral thigh, with specific dosing of 0.3-0.5 mg for adults and children ≥30 kg, and 0.01 mg/kg (maximum 0.3 mg) for children <30 kg. 1

Dosing Guidelines by Weight

• Adults and children ≥30 kg (66 lbs):

  • Dose: 0.3-0.5 mg epinephrine
  • Concentration: 1:1000 (1 mg/mL)
  • Volume: 0.3-0.5 mL
  • Route: Intramuscular injection in the anterolateral thigh
  • Frequency: Can be repeated every 5-10 minutes as necessary 1, 2

• Children <30 kg (66 lbs):

  • Dose: 0.01 mg/kg, up to maximum 0.3 mg
  • Concentration: 1:1000 (1 mg/mL)
  • Volume: 0.01 mL/kg, up to maximum 0.3 mL
  • Route: Intramuscular injection in the anterolateral thigh
  • Frequency: Can be repeated every 5-10 minutes as necessary 1, 2

Administration Considerations

Route of Administration

The intramuscular route in the anterolateral thigh is strongly preferred over subcutaneous administration. While the FDA label mentions both routes 2, evidence indicates that intramuscular administration in the mid-outer thigh provides more rapid and reliable absorption 3, 4.

Injection Site

The mid-outer thigh (vastus lateralis muscle) is the recommended injection site 3, 1. Do not inject into buttocks, digits, hands, or feet as this may lead to poor absorption or tissue damage 2.

Timing

Prompt administration of epinephrine is critical for preventing fatal outcomes. Delays in administration are associated with increased mortality 3, 4. Epinephrine should be given immediately upon recognition of anaphylaxis 3, 1.

Special Populations

Infants and Young Children

The clinical criteria for anaphylaxis have not been validated in infants 3. For very young children weighing less than 15 kg, standard auto-injector needle lengths may be too long, potentially resulting in intravascular injection 5. Consider using weight-appropriate devices when available.

Obese Patients

In obese patients, standard auto-injector needle lengths may be too short to reach muscle tissue 5. In such cases, ensure proper injection technique or consider alternative delivery methods to achieve intramuscular administration.

Monitoring and Follow-up

After administering epinephrine:

• Monitor the patient closely for at least 4-6 hours for potential biphasic reactions 1
• Position the patient supine with legs elevated if hypotensive 1
• Be prepared to administer a second dose if symptoms persist or worsen (6-19% of pediatric patients require a second dose) 1
• Activate emergency response system (call 911) for transport to an emergency department 3, 1

Common Pitfalls to Avoid

1. Delayed administration: Failure to inject epinephrine promptly is a major contributor to anaphylaxis fatalities 4.
2. Incorrect route: Using subcutaneous instead of intramuscular injection can delay onset of action 4.
3. Inappropriate injection site: Injecting into digits, hands, feet, or buttocks rather than the thigh can lead to poor absorption or complications 2.
4. Underdosing: Particularly in adults, using pediatric doses can result in inadequate treatment.
5. Fear of side effects: Concern about adverse effects should not prevent timely administration of epinephrine in anaphylaxis, as the benefits far outweigh the risks 3, 4.

Remember that epinephrine is the cornerstone of anaphylaxis management, and no other medication has similar life-saving pharmacologic effects in multiple organ systems 4. While adjunctive therapies like antihistamines and corticosteroids may be used, they should never delay or replace epinephrine administration 1.