Adrenaline (epinephrine) is the emergency treatment for a severe reaction. If it’s given quickly, it can treat the features of anaphylaxis by acting on adrenoceptors.
Allergic reactions vary in severity. So, in its 2016 guidelines, the British Society of Allergy and Clinical Immunology (BSACI) suggests that people who should be considered for long-term provision of an adrenaline auto-injector include those:
...who have suffered an anaphylactic reaction where the cause is unknown (idiopathic anaphylaxis)
...who have suffered an anaphylactic reaction where the known allergic trigger cannot easily be avoided
...who are allergic to high-risk allergic triggers, for example nuts, with other risk factors also present, such as asthma, even if the reaction was relatively mild
...who had a reaction in response to trace amounts of the allergic trigger
...where an anaphylactic reaction triggered by food is only likely to occur if that food is eaten around the time of physical exercise (known as Food-Dependant Exercise-Induced Anaphylaxis or FDEIA).
...where other significant risk factors are present (such as asthma in someone with a food allergy).
In its 2016 guidelines, the BSACI suggests the following:
0.3mg *0.3 mg is more appropriate for a smaller child > 12 years. **0.3 mg may be more appropriate for some children, for example over 25 kg.
In its 2017 prescribing guidelines, The UK’s Medicines and Healthcare products Regulatory Agency (MHRA), recommends prescribing two adrenaline auto-injectors, and patients should carry these at all times.
Because the course of severe allergic reactions is varied and unpredictable, it is difficult to define when adrenaline is best administered. The UK Resuscitation Council recommends giving adrenaline as soon as there is stridor (noisy breathing), respiratory distress, wheezing or clinical signs of shock. Urgent transfer to hospital is vital.
Unwanted effects are rare when appropriate doses of adrenaline are given. However, prescribers should consider all co-existing medical conditions and check for potential interactions. For example, beta-blockers and ACE inhibitors may hinder treatment.
When prescribing medicines for people with food allergies, check the ingredients and excipients to ensure the food allergens they react to are not present.
Adrenaline injectors have expiry dates and may be less effective after that date. Therefore, it is helpful to do a regular audit of prescribed adrenaline to identify patients whose last prescription was more than two years ago. The MHRA have also produced an advice sheet to give to patients, and manufacturers have an expiry alert service.
Epipen has a spring-loaded concealed needle that delivers a single measured dose when the pen is jabbed against the muscle of the outer thigh. Distributor: Meda Pharmaceuticals Ltd, Skyway House, Parsonage Road, Takeley, Bishop’s Stortford CM22 6PU. Tel 0845 460 0000. EpiPen delivers a 300mcg dose for adults and children weighing over 25kg. Junior versions deliver a 150mcg dose for infants and children who weigh between 7.5kg and 25kg.
Jext is a single-use adrenaline auto-injector. It has a locking needle shield which engages after use, which is designed to protect against accidental needle stick injury. Distributor: ALK-AbellÃ³ Ltd, 1 Manor Park, Manor Farm Road, Reading, Berkshire RG2 0NA. Tel: 0118 903 7940. Jext delivers a 300mcg dose for adults and children weighing over 30kg. Junior versions deliver a 150mcg dose for people who weigh between 15kg and 30kg.
Emerade is a pre-filled syringe encased in an auto-injector. It delivers a single dose of adrenaline when pressed against the muscle of the outer thigh. Distributor: Bausch + Lomb UK Limited 106-114 London Road Kingston upon Thames KT2 6TN United Kingdom. Tel: +44 (0)208 781 0001 Emerade 150mcg delivers 150mcg for children weighing between 15kg and 30kg —. Emerade 150mcg is currently unavailable. Emerade 300mcg or Emerade 500mcg deliver 150mcg or 500mcg for patients weighing over 30kg. Children weighing less than 15kg may be prescribed an injector at the prescriber’s discretion.
AllergyWise is our series of e-learning courses, providing an easy way to learn about anaphylaxis and how to manage severe allergies.
We have three courses available for healthcare professionals covering topics such as early recognition of symptoms, emergency treatment, using auto-injectors, and patient management.