Adrenaline (Anaphylaxis Protocol)

How it works

By stimulating alpha-1 receptors it reverses vasodilation and reduces mucosal oedema, while beta-1 and beta-2 stimulation supports cardiac output and relieves bronchospasm, counteracting the core features of anaphylaxis.

Prescribing in practice

• In anaphylaxis the route is intramuscular into the anterolateral thigh and must be given without delay; the much more concentrated cardiac-arrest intravenous strength must never be used for intramuscular anaphylaxis treatment.
• Repeat the intramuscular dose after a short interval if there is no improvement, and escalate to senior/critical-care support with consideration of an intravenous infusion only by experienced clinicians.
• Use a children's formulary for age- and weight-appropriate intramuscular dosing in paediatric anaphylaxis.

Monitoring

Monitor airway, breathing, circulation, oxygen saturation and ECG continuously, observing for biphasic reactions after initial recovery.

Counselling the patient

• Adrenaline is the priority treatment; antihistamines and steroids are second-line and must not delay it.
• Advise prolonged observation because symptoms can recur hours later.
• Arrange auto-injector provision, training and allergy follow-up before discharge.

Evidence & guidelines

Intramuscular adrenaline is the cornerstone of anaphylaxis management in Resuscitation Council UK guidance and NICE guideline CG134.