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

Adrenaline Dosing in Anaphylaxis

Administer epinephrine (adrenaline) 0.3-0.5 mg intramuscularly in the anterolateral thigh for adults and children ≥30 kg, or 0.01 mg/kg (maximum 0.3 mg) for children <30 kg, and repeat every 5-15 minutes as needed. 1, 2

Adult Dosing

• Give 0.3-0.5 mg of epinephrine (1:1000 concentration) intramuscularly into the anterolateral aspect of the thigh. 1, 2
• Repeat the dose every 5-15 minutes as needed based on patient response. 1, 2
• Approximately 6-19% of patients will require a second dose of epinephrine. 3, 1

Pediatric Dosing

For children weighing <30 kg (66 lbs): Give 0.01 mg/kg (0.01 mL/kg of 1:1000 concentration) intramuscularly, up to a maximum of 0.3 mg. 1, 4, 2

For children weighing ≥30 kg: Give 0.3-0.5 mg intramuscularly. 2

Autoinjector-Specific Dosing

• Children 7.5-25 kg: Use 0.15 mg epinephrine autoinjector. 4
• Children ≥25 kg: Use 0.3 mg epinephrine autoinjector. 4
• Infants <7.5 kg: The 0.15 mg autoinjector exceeds the recommended 0.01 mg/kg dose (representing a twofold dose), but most pediatricians still prescribe it due to the challenges and delays associated with drawing up doses from vials, which can take 3-4 minutes and often result in inaccurate or completely missed doses. 3, 4

Route of Administration

Intramuscular injection into the anterolateral thigh (vastus lateralis muscle) is the preferred route because it produces rapid peak plasma concentrations compared to subcutaneous administration. 1, 4

When to Use IV Epinephrine

Reserve intravenous epinephrine for:

• Patients in anaphylactic shock when an IV line is already in place. 1
• Cardiac arrest or profound hypotension unresponsive to IM epinephrine and fluid resuscitation. 1, 4

For continuous IV infusion: Add 1 mg (1 mL of 1:1000) epinephrine to 1000 mL of 0.9% normal saline, starting at 2 μg/min and titrating up to 10 μg/min according to blood pressure, cardiac rate, and oxygenation. 1

Repeat Dosing Algorithm

If symptoms persist or recur after the first dose:

• Give a second injection 5-15 minutes after the first dose. 3, 1, 5
• A third dose is needed infrequently but can be given at the same interval if necessary. 3, 4

Indications for subsequent doses include:

• Severe or rapidly progressive anaphylaxis. 3
• Failure to respond to the initial injection due to delayed administration, inadequate initial dose, or suboptimal route. 3

Critical Safety Points

There are no absolute contraindications to epinephrine use in anaphylaxis, even in elderly patients with comorbidities. 1

Common Pitfalls to Avoid

• Never delay epinephrine administration due to fear of adverse effects—delayed injection is associated with poor outcomes and fatality. 5, 6
• Do not substitute antihistamines or bronchodilators for epinephrine—these provide only adjunctive treatment. 5
• Do not inject into buttocks, digits, hands, or feet—this can cause serious complications. 2
• Do not use subcutaneous route—onset of action is potentially delayed compared to intramuscular injection. 6

Expected Pharmacologic Effects

Common effects include transient pallor, tremor, anxiety, palpitations, sweating, dizziness, nausea, and headache—these are similar to the "fight or flight" response and should not deter treatment. 3, 1, 2

Post-Administration Management

• Position the patient on their back or in a position of comfort if respiratory distress/vomiting is present, with elevated lower extremities. 5
• Do not allow standing, walking, or running. 3
• Call for emergency assistance (911/EMS) immediately. 5
• Transport to an emergency department for monitoring, even after successful treatment—observe for at least 6 hours as biphasic reactions can occur. 5