Every year thousands of Canadians who suffer from anaphylaxis rely on epinephrine injections in the event of the sudden onset of a severe allergy attack.
However according to the EpiPen website, these life-saving injections have a limited shelf life. While they should have a minimum of 12 months before expiry, some EpiPen and EpiPen Jr auto-injectors could sometimes have a shorter expiry date.
But is it possible that epinephrine injectors could last longer than what’s advertised?
According to one study published in the Annals of Internal Medicine, it may be.
The study explains that the active ingredient in these injectors (like the EpiPen) is epinephrine, also known as adrenaline. This is a hormone used to relax the muscles and open the airways, as well as reduce swelling during major allergic reactions.
In their study, a team of researchers at the University of California, San Diego measured the epinephrine concentration of 40 EpiPens that were past their expiration date.
That’s when they found that 29 months after the expiration, the pens still contained at least 90 per cent of the amount of epinephrine that’s listed on the packaging. Even after 50 months — or more than four years — the pens were still at 84 per cent.
This isn’t the first study to look at epinephrine auto-injectors and their shelf life.
A 2015 study by the University of Manitoba and Florida State University also found that some auto-injectors contained more than 90 per cent of their listed dose up to two years after the expiry date.
Despite building evidence from several studies over the years showing EpiPen’s potency of 90 per cent or higher after the listed expiration date, EpiPen’s website says it does not “recommend using an expired product.”
“The question I get a lot from patients is if the EpiPen’s expired, and it’s past the expiry date, what would happen if they used it,” Dr. David Fischer, allergist and president of the Canadian Society of Allergy and Clinical Immunology, told Global News. “My answer has always been that if my choice is between an expired EpiPen and nothing, I would always choose to give [the EpiPen].”
When an EpiPen is expired, Fischer explains that it doesn’t mean that it goes bad “like potato salad,” but that it’s just it’s less potent.
“There are other drugs out there that may last longer than their expiry date as well,” Fischer says. “It’s just that there has to be some sort of ‘best before’ date listed … But it’s also a very important drug and we don’t want there to be any margin of error.”
But when it comes to taking epinephrine shots, there are other ways in which people can hurt their chances of getting the full benefits of the shot — like how to work it and when it take it.
“We have to make sure people can actually work it,” Fischer says. “They have to know where the needle and safety cap is and know how to administer it properly to the correct area because if you do that incorrectly, it’s no help whatsoever and potentially harmful. The second thing is to know when to give it.”
Some people sometimes choose to forego taking the shot because they don’t believe their reactions are severe enough, Fischer says.
“Certainly if there are any symptoms that involve the airway — so coughing, wheezing, choking — or anything that involves the possibility of blood pressure being low, which can be anything from light-headedness, dizziness or even just profound tiredness, it should be taken,” Fischer says. “So sometimes people are faced with these symptoms and choose to take an antihistamine, and that’s something we’re trying to get people to do differently.”
According to the Canadian Institute for Health Information (CIHI), there were about 170,000 allergy-related visits to Canadian emergency rooms in 2013-2014. Visits for anaphylaxis specifically represented about eight per cent of all allergic reactions.
CIHI also found a 64 per cent increase in the rate of Canadians who were dispensed a prescribed epinephrine auto-injector between 2006 and 2014.