Understanding Epinephrine 1:100 Concentration
Epinephrine 1:100 means 1 gram of epinephrine dissolved in 100 mL of solution, which equals 10 mg/mL—this is an extremely concentrated formulation that is NOT used in modern clinical practice and should never be confused with the standard concentrations of 1:1,000 (1 mg/mL) or 1:10,000 (0.1 mg/mL). 1
Standard Epinephrine Concentrations in Clinical Use
The ratio notation describes how many milliliters of solution contain 1 gram of drug:
1:1,000 concentration = 1 gram per 1,000 mL = 1 mg/mL (formerly called "1:1000 solution," now labeled as 1 mg/mL for intramuscular use or inhalation) 2
1:10,000 concentration = 1 gram per 10,000 mL = 0.1 mg/mL (formerly called "1:10,000 solution," now labeled as 0.1 mg/mL for intravenous use) 2
1:100 concentration = 1 gram per 100 mL = 10 mg/mL (not a standard clinical formulation)
Critical Safety Considerations
The 1:100 concentration represents a 10-fold higher concentration than the standard 1:1,000 intramuscular formulation, making it dangerously concentrated for typical clinical applications. 1
Common Pitfalls to Avoid:
Decimal point errors are identified as high-risk practices that can result in 10-fold medication errors, particularly dangerous with epinephrine 2
Never confuse 1:1,000 with 1:10,000 concentrations—using 1:1,000 intravenously when 1:10,000 is indicated would deliver 10 times the intended dose 1
Always verify the concentration before administration, as the simple misplacement of a decimal point or confusion between ratio notations can be fatal 2
Standard Clinical Formulations
For Intramuscular/Subcutaneous Use:
- 1:1,000 (1 mg/mL) is the standard concentration for anaphylaxis treatment, administered as 0.3-0.5 mg (0.3-0.5 mL) for adults or 0.01 mg/kg (0.01 mL/kg) for children in the anterolateral thigh 1, 3
For Intravenous Use:
- 1:10,000 (0.1 mg/mL) is the standard concentration for cardiac arrest, administered as 1 mg (10 mL) IV push every 3-5 minutes 1
Preparing Diluted Epinephrine ("Dirty Epinephrine"):
- To create 1:10,000 from 1:1,000: draw up 1 mL of 1:1,000 epinephrine (1 mg) and add 9 mL of normal saline to create 10 mL of 1:10,000 solution (0.1 mg/mL or 100 mcg/mL) 1
Why 1:100 Is Not Used
A 1:100 concentration would be excessively concentrated at 10 mg/mL, creating unacceptable risk for:
Severe cardiovascular complications including hypertension, tachycardia, and arrhythmias if administered systemically 1
Catastrophic dosing errors if mistaken for standard concentrations 2
No clinical indication exists for such a concentrated formulation in emergency or routine care 1, 4
If you encounter a reference to "epinephrine 1:100," immediately verify the actual concentration with pharmacy and do not administer until the correct formulation is confirmed. 2