Epinephrine Dosing for Anaphylaxis
For anaphylaxis, epinephrine should be administered at a dose of 0.3-0.5 mg (0.3-0.5 mL of 1:1000 solution) intramuscularly in the anterolateral thigh for adults and children ≥30 kg, and 0.01 mg/kg (0.01 mL/kg of 1:1000 solution) up to 0.3 mg maximum for children <30 kg, repeated every 5-10 minutes as necessary. 1, 2
Dosing Guidelines by Weight
| Patient Category | Epinephrine Dose | Concentration | Volume |
|---|---|---|---|
| Adults and children ≥30 kg | 0.3-0.5 mg | 1:1000 (1 mg/mL) | 0.3-0.5 mL |
| Children <30 kg | 0.01 mg/kg (max 0.3 mg) | 1:1000 (1 mg/mL) | 0.01 mL/kg (max 0.3 mL) |
Administration Details
- Route: Intramuscular (IM) injection is preferred over subcutaneous (SC) 2, 3
- Site: Anterolateral thigh (vastus lateralis muscle) 1, 3
- Frequency: May repeat every 5-10 minutes as necessary if symptoms persist 1, 2
- Concentration: Use 1:1000 (1 mg/mL) solution for IM/SC administration 2
Important Clinical Considerations
- First-line treatment: Epinephrine is the first-line treatment for anaphylaxis with no absolute contraindications in this setting 2
- Timing: Early administration is critical; delayed epinephrine administration is associated with increased mortality 2, 3
- Second dose: Approximately 8-28% of patients may require a second dose of epinephrine when symptoms fail to resolve after the initial dose 4
- Avoid alternative routes: Inhalation of epinephrine is not an effective substitute for injection in anaphylaxis 5
- Monitoring: After administration, patients should be monitored for vital signs, including blood pressure, heart rate, and oxygen saturation 3
Special Populations
- Elderly patients and those with underlying cardiac disease, hyperthyroidism, Parkinson's disease, diabetes, and pheochromocytoma require careful monitoring due to increased risk of adverse effects 3, 1
- Medication interactions: Use with caution in patients taking sympathomimetic agents, cardiac glycosides, tricyclic antidepressants, MAO inhibitors, and beta-blockers 1, 3
Common Adverse Effects
- Anxiety, restlessness, tremor, dizziness, sweating, palpitations, pallor, nausea, vomiting, and headache 1
- Serious but rare effects include ventricular arrhythmias, rapid blood pressure increases, and angina 3, 1
Post-Administration Care
- All patients who receive epinephrine for anaphylaxis should be transported to an emergency department for observation (typically 4-6 hours) 3
- Extended observation is recommended for patients requiring more than one dose of epinephrine 3
Remember that antihistamines and corticosteroids are second-line agents and should not replace epinephrine as the primary treatment for anaphylaxis 2, 3.