Doctors do not know how to give live-saving injections to patients with dangerous allergic reactions, researchers have found.
Adrenaline injections must be given after severe allergic reactions
Adrenaline shots are given to patients who suffer anaphylactic shocks, which require immediate treatment.
But researchers from St Helier Hospital in Surrey found none of the 50 GPs questioned knew how they should be used.
They also found many patients did not know how to use the devices.
Researchers studied how 60 people at risk of severe allergic reactions, including 46 children, were informed about how to give adrenaline injections by doctors, and the GPs own knowledge of the anaphylaxis devices.
All of the GPs had prescribed the Epipen auto-injecting device, which are preloaded with a shot of adrenaline.
But only one knew how to use it - because he had experienced anaphylaxis himself.
None of the GPs had shown their patients how or when to use the device. Most asked the practice nurse to do so, but a fifth made no provision for training the patient.
All the doctors knew that the adrenaline shot should be given if the patient had a serious faint, choked, or had a severe asthmatic reaction.
But a quarter incorrectly said it was not necessary for the patient to go straight to hospital afterwards because the adrenaline only offers temporary relief.
'A few seconds'
The researchers also found patients were largely unaware of when and how to give the injections.
Only two of the 14 adults and the parents of only 16 of the 46 children were aware of how to use injectable adrenaline.
Overall, fewer than a third of patients or parents had adequate knowledge of when and how to use the device.
Experts say the Epipen should be given by simply holding the barrel and pressing the whole pen down into the thigh.
Dr Amalak Bansol, a clinical immunologist at Epsom and St Helier NHS Trust in Carshalton, Surrey who worked on the research, told BBC News Online: "It only takes a few seconds to show patients how to use the pen.
"But when you look at the patients, very few of them know how to use the pen, and very few of the parents can either.
"Somewhere between the GP prescribing the pen and the patient receiving it, there is a breakdown of communication."
He said patients who needed the Epipen should be referred by their GP to a specialist centre for a full assessment.
David Reading, director of the Anaphylaxis Campaign, told BBC News Online: "This research doesn't surprise us at all.
"Unfortunately GPs get next-to-no training in allergy as part of their medical education.
"And the person who misses out is the allergy patient, who is often left disheartened and bewildered."
He said patients could benefit from being seen at a specialist centre - but there were too few in the country to cope.