When Lee Cantrell, a toxicologist who helps run the California Poison Control System, and Roy Gerona, a University of California, San Francisco researcher who specialises in analysing chemicals, started testing leftover stocks of pills from the 1960s, they were surprised to find that “a dozen of the 14 compounds were still as potent as they were when they were manufactured, some at almost 100% of their labeled concentrations.”
If you followed the EpiPen controversy–manufacturer Mylan increased the price of the life-saving injection from $100 to $600 in seven years–you would know how wasteful expiry dates would be in its case. But when Cantrell and Gerona tested 40 EpiPens that had expired up to four years ago, they found that “24 of the 40 expired devices contained at least 90% of their stated amount of epinephrine, enough to be considered as potent as when they were made. All of them contained at least 80% of their labeled concentration of medication.” Not only were the injections old, they had been stored sub-optimally in places like the bathroom or a car glove box. In an emergency , these expired medicines could have saved lives.
“The term ‘expiration date’ was a misnomer,” says the article. “The dates on drug labels are simply the point up to which the FDA and pharmaceutical companies guarantee their effectiveness, typically at two or three years. But the dates don’t necessarily mean they’re ineffective immediately after they ‘expire’.”
Even manufacturers sometimes show expiry dates are not cast in stone. That’s what happened in June, when Pfizer extended the expiry dates for batches of its injectable atropine, dextrose, epinephrine and sodium bicarbonate by six months to a year because of shortages.
Cantrell and Gerona had published their findings in Archives of Internal Medicine in 2012, but the arbitrary way of setting expiry dates has not changed in the five years since. Pharmaceutical companies obviously don’t want drugs to `live’ longer because that will hit their replacement sales.