From the Guidelines
The standard dose of epinephrine for anaphylaxis is 0.01 mg/kg of a 1:1000 solution, up to a maximum of 0.5 mg in adults and 0.3 mg in children, administered intramuscularly in the anterolateral thigh. This dose can be repeated every 5-15 minutes as needed if symptoms persist 1. The intramuscular route is preferred over subcutaneous administration because it provides faster absorption and higher plasma concentrations. Epinephrine autoinjectors come in fixed doses, but the specific dose should be determined based on the patient's weight and medical history.
Key Considerations
- Epinephrine is the first-line treatment for anaphylaxis and should be administered promptly at the first sign of symptoms 1.
- The dose of epinephrine should be individualized based on the patient's weight and medical history, with a maximum dose of 0.5 mg in adults and 0.3 mg in children 1.
- Patients should be instructed to seek immediate medical attention after administering epinephrine, even if symptoms improve, as biphasic reactions can occur 1.
Administration Route
- The intramuscular route is preferred over subcutaneous administration because it provides faster absorption and higher plasma concentrations 1.
- The anterolateral thigh is the recommended site for intramuscular injection of epinephrine 1.
Special Considerations
- Patients with cardiovascular disease, asthma, or other comorbid conditions may require special consideration when administering epinephrine 1.
- Epinephrine should be used with caution in patients taking beta-blockers, but it is still the preferred treatment for anaphylaxis in these patients 1.
From the FDA Drug Label
DOSAGE AND ADMINISTRATION Anaphylaxis: Adults and Children 30 kg (66 lbs) or more: 0.3 to 0.5 mg (0.3 to 0.5 mL) intramuscularly or subcutaneously into anterolateral aspect of the thigh every 5 to 10 minutes as necessary Children 30 kg (66 lbs) or less: 0.01 mg/kg (0.01 mL/kg), up to 0.3 mg (0.3 mL), intramuscularly or subcutaneously into anterolateral aspect of the thigh every 5 to 10 minutes as necessary
The most common epinephrine doses in an anaphylaxis are:
- 0.3 to 0.5 mg for adults and children 30 kg (66 lbs) or more
- 0.01 mg/kg (up to 0.3 mg) for children 30 kg (66 lbs) or less 2
From the Research
Epinephrine Doses in Anaphylaxis
- The standard dose of epinephrine for anaphylaxis is 0.3 to 0.5 mL of 1:1000 dilution intramuscularly for adults and 0.01 mg/kg for children, given in the lateral thigh 3
- Epinephrine remains the drug of choice and should initially be administered intramuscularly, into the anterolateral thigh, as soon as the diagnosis is suspected 4
- For patients unresponsive to repeated intramuscular injections, a continuous infusion of epinephrine should be started 4
Second Dose of Epinephrine
- There are instances where a single dose of epinephrine does not relieve symptoms and a second dose may be required to further mitigate symptoms and preserve life 5
- A scoping review found that two or more doses of epinephrine were required in 8% of 582 patients and 28% of 18 patients, respectively, with anaphylaxis requiring treatment with epinephrine 5
- It is reasonable to administer a second dose when symptoms of severe anaphylaxis fail to resolve following an initial dose 5
Administration and Treatment
- Epinephrine autoinjectors can be used by the patient him/herself 6
- Antihistamines and corticosteroids are second-line medications and should never be given in lieu of, or prior to, epinephrine 4
- Aggressive fluid resuscitation should also be used to treat the intravascular volume depletion characteristic of anaphylaxis 4