From the Guidelines
The recommended dose of epinephrine for anaphylaxis is 0.01 mg/kg, up to 0.5 mg in adults and 0.3 mg in children, administered intramuscularly into the anterolateral thigh using a 1:1000 (1 mg/mL) concentration. This dose can be repeated every 5-15 minutes if symptoms persist or worsen 1. For adults, this typically means 0.3-0.5 mg, while children typically receive 0.15 mg if they weigh 15-30 kg and 0.3 mg if they weigh more than 30 kg. Auto-injectors come in fixed doses: 0.15 mg for children weighing 15-30 kg and 0.3 mg for those over 30 kg, with 0.5 mg devices available for larger adults.
Key Considerations
- Epinephrine is the first-line treatment for anaphylaxis and should be administered promptly 1.
- The dose of epinephrine can be repeated every 5-15 minutes if symptoms persist or worsen 1.
- Antihistamines and glucocorticoids are considered second-line therapy and should not be used as a substitute for epinephrine 1.
- After administering epinephrine, the patient should be placed in a supine position with legs elevated (unless breathing is compromised), given supplemental oxygen if available, and have IV access established for fluid resuscitation.
Administration
- Epinephrine should be administered intramuscularly into the anterolateral thigh using a 1:1000 (1 mg/mL) concentration 1.
- The speed and precision gained from using an auto-injector may justify trade-offs in dosing accuracy, especially in infants weighing >7.5 kg 1.
Monitoring and Follow-up
- Patients who have experienced anaphylaxis should be monitored for at least 30 minutes after administering epinephrine to detect potential biphasic reactions 1.
- Extended clinical observation is suggested in a setting capable of managing anaphylaxis for patients with resolved severe anaphylaxis and/or those who need >1 dose of epinephrine 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 recommended dose for anaphylaxis is 0.3 to 0.5 mg for adults and children 30 kg or more, and 0.01 mg/kg (up to 0.3 mg) for children less than 30 kg, administered intramuscularly or subcutaneously every 5 to 10 minutes as necessary 2.
From the Research
Anaphylaxis Dose
- The dose of adrenaline (epinephrine) to be administered for anaphylaxis is 300-600 µg for an adult or 10 µg/kg for a child 3.
- The method of choice for administering adrenaline is by intramuscular injection with an autoinjector, which can be repeated every 10-15 minutes until there is a response 3.
- In some cases, a second dose of epinephrine may be required to further mitigate symptoms and preserve life, with studies showing that 8% to 28% of patients may require two or more doses of epinephrine 4.
- The safety of epinephrine for anaphylaxis has been evaluated, and it is considered safe when given at the correct dose by intramuscular injection, with the majority of dosing errors and cardiovascular adverse reactions occurring when epinephrine is given intravenously or incorrectly dosed 5.
Administration and Treatment
- The immediate treatment of patients with anaphylaxis involves removal of the trigger, early administration of intramuscular epinephrine, supportive care for the patient's airway, breathing, and circulation, and a period of observation for potential biphasic reactions 6.
- Adjunct medications, such as histamine H1 and H2 antagonists, corticosteroids, beta2 agonists, and glucagon, may be considered after epinephrine administration 6.
- Corticosteroids are frequently used in the management of anaphylaxis, although there is no compelling evidence to support or oppose their use, and they may reduce the length of hospital stay but do not reduce revisits to the emergency department 7.