Adrenaline injectors designed to treat potentially fatal allergic reactions are not simple enough to use, according to researchers.

In a study published in the July issue of the journal Allergy, more than half of parents of children with allergies failed to use their device correctly in a simulated emergency, six weeks after being trained.

Three similar and commonly-used devices, EpiPen, Anapen and Jext, all peformed poorly in the tests. A new device that plays audio instructions, Auvi-Q, had much better results, with 93 per cent of parents able to use it correctly, even without training. Auvi-Q is currently only available in North America.

Dr Robert Boyle from the Department of Medicine at Imperial College London, who led the study, said: “Our conclusion is that device design really matters. If we’re spending many millions of pounds a year on an emergency medical treatment carried by thousands of people in this country alone, then we need to be sure that we’re using a device that’s fit for purpose.”

Severe allergic reactions, known as anaphylaxis, cause around 20 deaths in the UK each year. The NHS in England spent £13.9 million on adrenaline autoinjectors in 2014.

In the first part of the study, 158 mothers of children with food allergies were randomly prescribed an EpiPen or Anapen and trained according to the manufacturer’s instructions. Six weeks after training, they were tested using the injector on a dummy. Only 42 per cent of those using Anapen and 43 per cent of those using Epipen administered the injection correctly. They were tested again after one year, with similar results. Common mistakes included failing to remove all the safety caps, and not pressing the device in for long enough to inject the full dose.

The participants were then switched to a different device: Anapen, EpiPen, a new version of EpiPen, Jext or Auvi-Q, without specialised training. Success rates were stable for parents who switched between similar devices, but fell for those who switched to a device with a different mechanism. However, success rates improved dramatically for parents who switched to Auvi-Q.

“These devices could save someone’s life in an emergency and they give patients peace of mind, but they need to be easy to use in a stressful situation. Our study suggests that the devices currently used in Europe do not meet the requirements,” said Dr Boyle.

On Friday, a review by the European Medicines Agency recommended several measures, including the introduction of more effective educational material, to ensure that patients and carers use adrenaline autoinjectors successfully.

References

T. Umasunthar et al. ‘Patients’ ability to treat anaphylaxis using adrenaline autoinjectors: a randomized controlled trial.’ Allergy, Volume 70, Issue 7, pages 855–863, July 2015; DOI: 10.1111/all.12628

NHS spending data: Health and Social Care Information Centre: Prescription Cost Analysis, England - 2014 [NS]