Adrenaline (Anaphylaxis Protocol)
Brand names: EpiPen, Emerade, Jext, Auvi-Q
This page concerns adrenaline (epinephrine) used under the anaphylaxis protocol, given by intramuscular injection into the anterolateral thigh as the immediate first-line treatment for anaphylaxis.
Adult dose
Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.
Contraindications
- Hypersensitivity to the active substance or to any of the excipients (contraindications are relative as the product is intended for use in life-threatening emergencies)
- Do not use in fingers, toes, ears, nose, genitalia or buttocks owing to the risk of ischaemic tissue necrosis
- Do not use if the solution is discoloured
Side effects
- Palpitations and tachycardia; at high dosage or in sensitive patients, cardiac dysrhythmia (sinus tachycardia, ventricular fibrillation/cardiac arrest), acute angina attacks and risk of acute myocardial infarction
- Pallor and coldness of the extremities; at high dosage, hypertension with risk of cerebral haemorrhage and vasoconstriction (cutaneous, extremities or kidneys)
- Headache, tremors, dizziness, syncope; anxiety, nervousness, fear, hallucinations
- Hyperglycaemia, hypokalaemia, metabolic acidosis
- Dyspnoea, nausea, vomiting, sweating, weakness, mydriasis
- Necrosis at the site of injection after repeated local injections
Interactions
- Halothane and other halogenated anaesthetics — avoid adrenaline or use with extreme caution, in view of the risk of inducing ventricular fibrillation (UK SPC section 4.4)
- Drugs antagonising the pressor effects: alpha-blockers (e.g. phentolamine), vasodilators such as nitrates, diuretics, antihypertensives, ergot alkaloids, phenothiazine antipsychotics (US labelling section 7.1)
- Drugs potentiating the pressor effects: sympathomimetics, beta-blockers (e.g. propranolol), tricyclic antidepressants, MAO inhibitors, COMT inhibitors, clonidine, doxapram, oxytocin (US labelling section 7.2)
- Drugs increasing arrhythmogenic potential: beta-blockers, cyclopropane and halogenated hydrocarbon anaesthetics, quinidine, antihistamines, exogenous thyroid hormones, diuretics, cardiac glycosides — observe for cardiac arrhythmias (US labelling section 7.3)
- Potassium-depleting drugs (corticosteroids, diuretics, theophylline) potentiate the hypokalaemic effects (US labelling section 7.4)
Clinical monograph
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.
Reference: Resuscitation Council UK Anaphylaxis Algorithm 2021; NICE CG134; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).
Related
Curated clinical cross-links plus same-class fallbacks.
- EDACS — Emergency Department Assessment of Chest Pain · Chest Pain
- ADAPT Protocol for Cardiac Event Risk · Chest Pain
- HIV Needle-Stick Risk Assessment Stratification Protocol (RASP) · HIV Post-Exposure
- FAST Exam Protocol — Focused Assessment with Sonography in Trauma · Trauma
- Westley Croup Score · Respiratory
- Difficult Airway Algorithm (DAS) · DAS 2015; Royal College of Anaesthetists
- Major Haemorrhage Protocol · NICE NG24; UK MHP guidelines
- New-Onset Atrial Fibrillation · ESC 2020 AF Guidelines; NICE NG196
- Hypertensive Emergency · ESC/ESH 2018 Hypertension Guidelines; NICE NG136
- Bradycardia Management · Resuscitation Council UK ABCDE; ESC 2021 Pacing Guidelines
- Ventricular Tachycardia / Fibrillation · Resuscitation Council UK ACLS; ESC 2022 Ventricular Arrhythmia Guidelines
Featured in these MRCEM clinical pathways
Adrenaline (Anaphylaxis Protocol) is a core drug in the following exam-focused workups on our sister siteReviseMRCEM.
MRCEM Primary / Intermediate / OSCE candidates: each pathway includes exam-style questions, RCEM/NICE citations, and FAQ summaries.