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Auto-injector / IM adrenaline for anaphylaxis Pregnancy: No contraindication in anaphylaxis — maternal resuscitation priority.

Adrenaline (Anaphylaxis Protocol)

Brand names: EpiPen, Emerade, Jext, Auvi-Q

Adult dose

Dose: 0.5 mg (0.5 mL of 1:1,000) IM into anterolateral thigh
Route: IM (anterolateral thigh — preferred site)
Frequency: Repeat after 5 min if no improvement
Max: 0.5 mg per dose (IM); IV adrenaline only in cardiac arrest or life-threatening anaphylaxis in monitored setting
Anaphylaxis (IM): 0.5 mg (500 mcg) IM every 5 min until improvement. NEVER give IV adrenaline unless monitored (cardiac arrest dose 1 mg). Auto-injector pens: EpiPen 300 mcg (adult), Jext 300 mcg, Emerade 300 mcg or 500 mcg. CALL 999. Observe minimum 6–12 hours for biphasic reaction.

Paediatric dose

Dose: 0.01 mg/kg
Route: IM
Frequency: Every 5 min if needed
Max: 0.5 mg/dose
Concentration: 1 mg/ml
<6 years: 150 mcg IM (EpiPen Jr / Jext 150 mcg). 6–12 years: 150 or 300 mcg depending on weight. >12 years and adult: 300–500 mcg. Weight-based: 0.01 mg/kg (max 0.5 mg). MHRA: prescribe by brand name (device-specific training required).

Dose adjustments

Renal

No dose adjustment required in emergency.

Hepatic

No dose adjustment required in emergency.

Paediatric weight-based calculator

<6 years: 150 mcg IM (EpiPen Jr / Jext 150 mcg). 6–12 years: 150 or 300 mcg depending on weight. >12 years and adult: 300–500 mcg. Weight-based: 0.01 mg/kg (max 0.5 mg). MHRA: prescribe by brand name (device-specific training required).

Clinical pearls

  • IM anterolateral thigh gives faster absorption than deltoid or buttock
  • Remove auto-injector needle safety cap and hold firmly against outer thigh for 10 seconds
  • RESUS Council Anaphylaxis algorithm: adrenaline → chlorphenamine → hydrocortisone (adrenaline is the ONLY priority first-line)
  • Biphasic anaphylaxis: observe minimum 6 hours, 12–24 hours if severe
  • Beta-blocker patients: may need glucagon 1–2 mg IV if adrenaline fails

Contraindications

  • No absolute contraindications in life-threatening anaphylaxis

Side effects

  • Tachycardia and palpitations
  • Hypertension
  • Tremor and anxiety
  • Pallor
  • Headache

Interactions

  • Beta-blockers — may require higher doses of adrenaline to achieve same response (glucagon may be needed as adjunct)

Monitoring

  • BP, HR, SpO2 continuously
  • Symptoms (urticaria, bronchospasm, BP)
  • 6–12 hour observation post-reaction

Reference: BNFc; BNF; Resuscitation Council UK Anaphylaxis Algorithm 2021; NICE CG134. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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