What is the recommended dose and administration route for double‑strength adrenaline (1 mg/mL) in adult and pediatric anaphylaxis?

Double-Strength Adrenaline (1 mg/mL) Dosing and Administration

Double-strength adrenaline (1 mg/mL, also called 1:1000 concentration) is the standard formulation for intramuscular injection in anaphylaxis, NOT for intravenous use—IV administration requires dilution to 1:10,000 or 1:100,000 concentration to prevent potentially lethal arrhythmias. 1, 2

Intramuscular Administration (First-Line Treatment)

Adult Dosing

• Dose: 0.3 to 0.5 mg (0.3 to 0.5 mL of 1 mg/mL solution) intramuscularly into the anterolateral thigh (vastus lateralis muscle) 1, 3, 4
• Maximum single dose: 0.5 mg per injection, regardless of body weight 5, 4
• Repeat dosing: Every 5 minutes as needed until symptoms resolve—there is no maximum number of doses 3, 5
• Approximately 10-20% of patients require more than one dose 5

Pediatric Dosing

• Dose: 0.01 mg/kg (0.01 mL/kg of 1 mg/mL solution) intramuscularly into the anterolateral thigh 1, 3, 4
• Maximum single dose: 0.3 mg for children weighing <30 kg; 0.5 mg for children ≥30 kg 1, 4
• Repeat dosing: Every 5 minutes as needed 3, 5

Critical Administration Points

• Route: Intramuscular injection at 90-degree angle into the anterolateral thigh achieves peak plasma concentrations in 8±2 minutes, compared to 34±14 minutes with subcutaneous deltoid injection 1, 3, 5
• Never delay: Administer immediately upon recognition of anaphylaxis—delayed epinephrine is associated with fatalities 3, 6, 7
• Can inject through clothing if necessary during emergency situations 3

Intravenous Administration (Reserved for Refractory Cases Only)

IV epinephrine should ONLY be used after failure of multiple IM doses plus IV fluid resuscitation, or during cardiac arrest—it carries significant risk of lethal arrhythmias and requires continuous hemodynamic monitoring. 1, 2

IV Infusion Preparation (Two Methods)

Method 1 (Standard):

• Add 1 mg (1 mL) of 1:1000 epinephrine to 250 mL D5W to yield 4.0 mcg/mL concentration 1, 2, 5
• Starting rate: 1-4 mcg/min (15-60 drops/min with microdrop apparatus) 1, 2
• Maximum rate: Titrate up to 10 mcg/min based on clinical response 1, 2

Method 2 (Alternative):

• Add 1 mg (1 mL) of 1:1000 epinephrine to 100 mL normal saline to create 1:100,000 solution (10 mcg/mL) 1, 2
• Starting rate: 30-100 mL/h (5-15 mcg/min) 1
• Maximum rate: Titrate up to 10 mcg/min (60 mL/h) 1

Pediatric IV Dosing

• Dose: 0.01 mg/kg (0.1 mL/kg of 1:10,000 solution; maximum 0.3 mg) 1, 2
• "Rule of 6" alternative: 0.6 × body weight (kg) = mg diluted to 100 mL saline; then 1 mL/h delivers 0.1 mcg/kg/min 1, 2, 5

Mandatory Monitoring for IV Administration

• Continuous hemodynamic monitoring is essential 1, 2
• In settings without hemodynamic monitoring: every-minute blood pressure measurements, continuous pulse monitoring, and ECG monitoring if available 2
• Most patients show symptomatic improvement and systolic BP >90 mmHg within 5 minutes of epinephrine infusion 2

Critical Safety Warnings

Common Pitfalls to Avoid

• Never confuse concentrations: 1:1000 (1 mg/mL) is for IM use; 1:10,000 (0.1 mg/mL) is for IV use—administering undiluted 1:1000 IV can cause fatal arrhythmias 1, 2, 5
• Do not inject into buttocks, digits, hands, or feet—risk of tissue necrosis and compartment syndrome 4
• Do not use subcutaneous route—absorption is significantly delayed compared to IM 1, 3
• Do not delay for "perfect" technique—prompt administration is more important than technical perfection 3
• Do not withhold in elderly or cardiac patients—there is no absolute contraindication to epinephrine in anaphylaxis 1, 3, 5

Potential Adverse Effects

• Tachyarrhythmias/ectopic beats, hypertension, anxiety, tremor, pallor, palpitations, headache 2, 4
• Risk of potentially lethal arrhythmias with IV administration 1, 2
• Extravasation can cause severe skin injury 2
• Rare cases of serious skin and soft tissue infections have been reported following injection 4

When to Escalate Beyond IM Epinephrine

Consider IV epinephrine infusion if:

• Patient fails to respond to multiple IM doses (typically 2-3 doses) 2, 3, 5
• Profound hypotension unresponsive to IV fluid resuscitation (1000-2000 mL normal saline bolus for adults) 1, 2, 5
• Cardiac arrest 1, 2

The number of IM doses should be determined by clinical response rather than an arbitrary maximum—if symptoms persist or progress, continue dosing every 5 minutes. 3, 5