What is a 1:1000 Epinephrine Solution?
A 1:1000 epinephrine solution contains 1 mg of epinephrine per 1 mL of solution (1 mg/mL). 1, 2
Concentration Breakdown
The ratio notation "1:1000" means:
- 1 gram of epinephrine in 1000 mL of solution
- This equals 1 mg per 1 mL (1 mg/mL)
- This is the more concentrated form of epinephrine used clinically
Critical Distinction: Two Standard Concentrations
Epinephrine is available in two concentrations, and confusing these can be fatal 1:
- 1:1000 (1 mg/mL) - More concentrated
- 1:10,000 (0.1 mg/mL) - More dilute (10-fold less concentrated)
Extreme caution must be exercised to select the appropriate concentration for the route of administration and clinical indication. Using 1:1000 when 1:10,000 is indicated (particularly for IV bolus) has caused anaphylaxis fatalities 3, 4.
Clinical Uses of 1:1000 Solution
The 1:1000 concentration is specifically used for:
Intramuscular/Subcutaneous Routes
- Anaphylaxis (IM preferred): 0.01 mg/kg of 1:1000 solution (maximum 0.3-0.5 mg), repeated every 5-20 minutes 1
- Severe asthma exacerbation (SC): 0.01 mg/kg of 1:1000 solution (maximum 0.3-0.5 mg), may repeat every 20 minutes up to 3 doses 1
Nebulized/Topical Routes
- Croup/laryngotracheobronchitis: 0.5 mL/kg of 1:1000 solution (maximum 5 mL) administered by nebulizer 1
- Topical hemostasis (ENT/dental surgery): Applied on pledgets for vasoconstriction 5, 6, 7
Endotracheal Route
- Older infants/children during CPR: 0.1 mg/kg of 1:1000 solution (maximum 10 mg) 1
Dosing Conversion Formula
To convert mg/kg dosage to mL/kg 1:
- 0.01 mg/kg = 0.1 mL/kg of 1:10,000 solution
- 0.1 mg/kg = 0.1 mL/kg of 1:1000 solution
Critical Safety Warnings
Route-Specific Dangers
Never administer 1:1000 solution as an IV bolus - this concentration is too strong for direct intravenous injection and can cause potentially lethal arrhythmias 3, 4. For IV use during cardiac arrest or profound hypotension, the 1:10,000 dilution should be used 1, 8.
When IV Epinephrine is Needed
If IV epinephrine is required (for profoundly hypotensive patients failing IM epinephrine and volume resuscitation), prepare an infusion by adding 1 mg (1 mL) of 1:1000 epinephrine to 250 mL D5W, yielding 4 mcg/mL 3. Start at 1-4 mcg/min and titrate 3.
Physical Characteristics
The 1:1000 solution is a clear, colorless, sterile solution that deteriorates rapidly on exposure to air or light, turning pink from oxidation and brown from melanin formation 2. Always check for discoloration before use.
Common Pitfall
The most dangerous error is selecting 1:1000 instead of 1:10,000 for IV bolus administration during resuscitation. Always verify the concentration matches the intended route before drawing up the medication 1, 4.