Are some patients getting the wrong dose of adrenaline? National data reveal gaps in dose switching 

A recent review of community adrenaline prescriptions from 2022-2024 has revealed that many people in England may be prescribed the lower-dose adrenaline auto-injector (AAI) when they should have been upgraded to the higher dose based on their age and weight. The study calls for reviews, age checks and automated alerts in primary care. 

Anaphylaxis is a serious allergic reaction that must be treated with adrenaline as quickly as possible to reverse potentially life-threatening symptoms. For this reason, people at risk of anaphylaxis are prescribed AAIs such as EpiPen® or Jext® to carry with them at all times.  

Why was the study needed? 

In the UK, there are two AAI doses: 150 micrograms (μg) for children up to 25-30kg, and 300μg dose for those weighing 25-30kg or more. The switch from the lower to the higher dose should happen when a child reaches around 25kg. However, there is currently no automatic system in place to alert primary healthcare professionals (such as GPs) when a patient has reached this point. As a result, some patients may not be moved to the higher dose when they should be. 

This is an issue because real-world cases show that delaying adrenaline treatment, or using the wrong dose during anaphylaxis, can be life-threatening. Healthcare professionals have long suspected that some people may still be carrying a lower-dose AAI when they should have been upgraded, so the researchers set out to find how common this problem is across England. 

How was the study done? 

Researchers at Newcastle University analysed prescription records for patients with a recent AAI prescription (between December 2022 to December 2024) to identify “non-standard” prescribing in the UK. That means patients who were likely to weigh more than 25–30kg but still received the lower 150μg dose. 

Because the NHS doesn’t regularly check patient weight, the researchers used age as a guide. They compared each patient’s age to growth charts to work out whether they likely weighed enough to need the higher dose. They also looked at whether the problem was worse in more deprived areas of England and checked how many AAIs were prescribed per prescription. 

What did the study find? 

The study found that of people still given the lower-dose AAI, between 1,700 (around 1 in 27) and 9,480 (around 1 in 5) were likely already above the weight where they should be using the higher 300μg AAI. If you apply the Resuscitation Council UK guideline that all children should switch at age 6, the number of people given the incorrect AAI rises to 23,059 people — nearly half. 

Other findings included: 

• AAI prescribing increased: patients with AAI prescriptions rose over 40% from 2015/16 to 2023/24. 

• Over 95% of patients received two or more AAI devices, in line with national guidance on quantity.  

• There were 2,137 patients (4.5%) who received only one AAI in their latest prescription.  

• A small number of very young children appeared to have 300μg AAIs prescribed despite being below the usual weight thresholds. 

• Most patients flagged as possibly on the wrong dose were young adults aged 12 to 22—a group at higher risk of serious allergic reactions.  

• Lower-dose prescriptions were also found across all adult age groups. 

What about differences across England? 

The study found big variations between different parts of England. Some areas had much higher rates of people on the wrong dose than others. There was also a link with deprivation: areas with higher deprivation had higher rates of people receiving the wrong dose. This suggests that healthcare inequalities in allergy care continue to exist, with more disadvantaged communities potentially receiving lower standards of treatment. 

What are the limitations? 

• The research doesn’t show the exact reason each pen was prescribed, so the researchers can’t be certain every pen was prescribed “incorrectly” — though AAIs are usually only prescribed for anaphylaxis. 

• They didn’t have actual patient weights, only age as a rough guide—so some patients might have been appropriately dosed even if their age suggests otherwise. 

• The data covers only NHS primary-care prescriptions in England (no private prescriptions, hospital-issued AAIs, or prescriptions from Scotland, Wales or Northern Ireland). 

What does this mean going forward?  

This research suggests that the current system for upgrading patients to higher AAI doses isn’t working reliably. Without automatic reminders in primary care, patients can remain on an outdated dose for years. The researchers recommend several steps: 

• Automated safety checks: primary care computer systems should flag patients over 14 years old who are still prescribed 150μg AAIs, since by that age nearly everyone should need the higher 300μg dose. 

• Age-based reviews: all patients should be reviewed at age 8 (when most children exceed 25-30kg), and again at ages 10 and 14, to check they’re on the right dose for their device brand. 

• Targeted action in deprived areas: NHS areas should identify patients on non-standard doses, with particular attention to more deprived regions. 

• Better communication: healthcare professionals need clearer guidance on when to switch doses. 

Key takeaways 

• The findings should be considered for the next update of national guidance on anaphylaxis. 

• Pharmacists could play a bigger role in informing patients about when to upgrade their dose. 

• All healthcare professionals should ensure anyone prescribed AAIs leaves with the appropriate dose for their weight. 

• If you or your child carry adrenaline, ask your GP whether it’s the right dose for your current weight — don’t assume a long-standing prescription is still correct, especially for young people and young adults. 

Read the full study here: Adrenaline Auto-Injector Prescribing in Primary Care in England: An Analysis of Non-Standard Dosing