What does 0.3-0.5 ml of a 1:1000 (one thousand) epinephrine solution mean and how to administer or dilute it?

Understanding 1:1000 Epinephrine Solution

A 1:1000 epinephrine solution means 1 gram per 1000 mL, which equals 1 mg per 1 mL—therefore, 0.3-0.5 mL of this solution delivers 0.3-0.5 mg of epinephrine and requires no dilution for intramuscular or subcutaneous administration. 1

What the Concentration Means

• 1:1000 = 1 mg/mL: This is the standard concentration for intramuscular/subcutaneous use 2, 1
• The solution comes ready-to-use in ampules and requires no preparation or dilution 1
• Do not confuse with 1:10,000 concentration (0.1 mg/mL), which is used for intravenous administration during resuscitation—using 1:1000 IV when 1:10,000 is indicated would deliver 10 times the intended dose 1

How to Administer 0.3-0.5 mL of 1:1000 Solution

For Adults and Children ≥30 kg (66 lbs):

• Draw up 0.3-0.5 mL directly from the ampule (maximum 0.5 mL per injection) 3
• Inject intramuscularly into the anterolateral thigh through clothing if necessary 3
• Use a needle at least 1/2 to 5/8 inch long to ensure intramuscular delivery 3
• The intramuscular route in the thigh is strongly preferred over subcutaneous or arm injection, as it achieves significantly higher peak plasma concentrations 4

For Children <30 kg (66 lbs):

• Dose is 0.01 mg/kg = 0.01 mL/kg of 1:1000 solution 2
• Maximum single dose: 0.3 mL (0.3 mg) 3
• Same intramuscular thigh administration 3

Repeat Dosing:

• May repeat every 5-10 minutes as necessary for anaphylaxis 3
• For severe asthma, may repeat every 20 minutes up to 3 doses 2
• Do not inject repeatedly at the same site due to risk of tissue necrosis from vasoconstriction 3

When Dilution IS Needed (Different Clinical Scenarios)

To Create 1:10,000 for IV Use During Resuscitation:

• Take 1 mL of 1:1000 solution (1 mg) and add 9 mL of normal saline to create 10 mL of 1:10,000 solution (0.1 mg/mL) 1
• This diluted concentration is used for IV administration during cardiopulmonary resuscitation 2

For Nebulized Administration in Croup:

• Use 0.5 mL/kg of undiluted 1:1000 solution (maximum 5 mL) in nebulizer 2
• No dilution required, but may be mixed with normal saline for nebulization 2

Critical Safety Points

• Inspect the solution before use: Do not use if colored, cloudy, or contains particulate matter 3
• Store at room temperature, protected from light and freezing 5
• Monitor patient clinically for reaction severity and cardiac effects after each dose 3
• When administering to children, hold the leg firmly to minimize injection-related injury 3
• Epinephrine is the first-line, life-saving medication for anaphylaxis and should be administered promptly once anaphylaxis is suspected 6, 7