Intramuscular Epinephrine 1:1000 (1 mg/mL) - No Dilution Required
For intramuscular administration, the 1:1000 (1 mg/mL) epinephrine preparation is given undiluted directly into the anterolateral thigh. This is explicitly confirmed by both FDA labeling and multiple clinical guidelines 1, 2, 3.
Direct Administration Protocol
The FDA-approved labeling for Adrenalin® specifically states: "0.3 to 0.5 mg (0.3 mL to 0.5 mL) of undiluted Adrenalin® administered intramuscularly" for adults and children ≥30 kg, and "0.01 mg/kg (0.01 mL/kg) of undiluted Adrenalin® administered intramuscularly" for children <30 kg 3. The term "undiluted" is explicitly used in the official drug labeling, leaving no ambiguity.
Dosing Specifics
Adult and pediatric dosing from the 1:1000 concentration:
- Adults/children ≥30 kg: 0.3-0.5 mg (0.3-0.5 mL) IM, maximum 0.5 mg per injection 1, 3
- Children <30 kg: 0.01 mg/kg (0.01 mL/kg) IM, maximum 0.3 mg per injection 1, 3
- Repeat every 5-15 minutes as needed for persistent anaphylaxis symptoms 1, 2
The 2020 AHA Guidelines explicitly state: "The recommended dose of epinephrine in anaphylaxis is 0.2 to 0.5 mg (1:1000) intramuscularly" 1. The 2024 immunotherapy guideline reinforces this: "Intramuscular epinephrine should be given at a dose of 0.01 mg/kg of 1 mg/mL (1:1000), up to 0.5 mg in adults and 0.3 mg in children" 2.
Critical Distinction: IM vs IV Concentrations
The 1:1000 concentration is ONLY for intramuscular/subcutaneous routes - never intravenous. This is a critical safety point emphasized across all guidelines 4:
- IM/SC route: Use 1:1000 (1 mg/mL) undiluted
- IV route: Use 1:10,000 (0.1 mg/mL) concentration at much lower doses (0.05-0.1 mg for anaphylactic shock) 1
The 2008 Pediatrics guideline warns: "Use caution to ensure selection of the appropriate concentration for the route of administration" 4. Administering the 1:1000 concentration intravenously can cause life-threatening arrhythmias and severe hypertension.
Administration Technique
Inject into the anterolateral thigh (vastus lateralis muscle) through clothing if necessary 1, 2, 3. This site produces more rapid peak plasma epinephrine concentrations compared to the upper arm 5. Use a needle at least 1/2 to 5/8 inch long to ensure intramuscular delivery 3.
For children, hold the leg firmly to minimize injection-related injury 3. Do not inject repeatedly at the same site due to risk of tissue necrosis from vasoconstriction 3.
Common Pitfall to Avoid
Do not confuse or dilute the 1:1000 IM preparation with the 1:10,000 IV preparation. The concentrations differ by 10-fold, and using the wrong concentration for the wrong route can result in either severe underdosing (if using 1:10,000 IM) or life-threatening overdose (if using 1:1000 IV). Always verify the concentration matches the intended route before administration.