Drug expiry dates: Should you use outdated medicine?
July 8, 2011 11:04 by Dr. Lorne Brandes
A recent e-mail from a friend immediately “caught my eye” (the pun will be evident in a moment). He thought I would be interested in a 2002 article , entitled, “Do Medications Really Expire?” by writer, Richard Altschuler.
“Does the expiration date on a bottle of a medication mean anything? If a bottle of Tylenol, for example, says something like ‘Do not use after June 1998,’ and it is August 2002, should you take the Tylenol? Should you discard it? Can you get hurt if you take it? Will it simply have lost its potency and do you no good?” Altschuler asked.
“In other words, are drug manufacturers being honest with us when they put an expiration date on their medications, or is the practice of dating just another drug industry scam, to get us to buy new medications when the old ones that purportedly have ‘expired’ are still perfectly good?” he added.
I paused to reflect on those important questions. A few weeks earlier, my ophthalmologist had given me some sample eye drops. “According to the date on the box, they expired last month. Are you okay with that, or would you prefer that I write you a new prescription?” she asked. “I… think… I’m okay with the samples,” I replied hesitantly.
There followed a discussion about how it makes no sense that a drug with an expiry date of December 31st suddenly stops working on January 1st. Yet, as I left her office, thanking her for the free samples, I wondered whether I might be playing Russian Roulette with my eye pressures.
Now, based on the information in my friend’s e-mail, I suspect that I wasn’t.
To begin, Altschuler explains that drug expiry dates are not a money grab cooked up by Big Pharma, but rather, the result of a 1979 federal law, mandated by the FDA.
He goes on to explain, “…the expiration date… specifies only the date the manufacturer guarantees the full potency and safety of the drug - it does not mean how long the drug is actually ‘good’ or safe to use…. [M]edical authorities uniformly say it is safe to take drugs past their expiration date - no matter how ‘expired’ the drugs purportedly are. Except for possibly the rarest of exceptions, you won't get hurt and you certainly won't get killed.”
Perhaps not hurt or killed. But what about potency? How long do drugs, such as those eye drops, remain effective? Happily, a more recent publication goes a long way in answering that question.
According to a comprehensive 2006 paper, published in the Journal of Pharmaceutical Sciences by scientists at the FDA’s Center for Drug Evaluation, we now know quite a lot about the shelf-life of many pharmaceuticals, thanks to the American military. Why?
Because the U.S. Department of Defense (DoD) maintains a billion dollar stash of drugs (called the Strategic National Stockpile), including a host of antibiotics, anesthetics, narcotics, anti-allergics, anti-toxins, anti-malarials, anti-convulsants, vaccines and intravenous solutions. It’s part of the DoD’s Medical Readiness Strategic Plan for war or natural disasters.
But just like the everyday consumer, the DoD’s drugs have those same expiry dates. Replacing such a huge cache of unopened/unused drugs every 3 to 5 years is not only potentially wasteful, but hugely expensive for the taxpayer. Therefore to gain a handle on the question of drug stability, the DoD, in conjunction with the FDA has, for the last twenty years, monitored 122 of its drugs in a shelf life extension program, known by the acronym “SLEP”.
Here’s how it works, as described in the journal paper: “Certain lots of drug[s] that are approaching their labeled expiration date are selected… [and]… subjected to a battery of tests… If a lot fails any [original] specification…the shelf life for that lot is expired. [If a drug lot passes all the tests] and the [predicted] remaining expiration period is longer than 1 year, the [drug lot] is granted a new expiration date.”
What has the program found? Fully 88% of the 3000 drug lots tested have an average extended shelf-life of 5.5 years beyond the original expiry date! Indeed, many pills, powders and liquids have been found to be stable for an extra ten or more years, while only 10 of the 122 drugs failed to gain an extension beyond their original expiry date. Even in those cases, the drug lots often failed for reasons other than loss of potency, such as a change in appearance.
So what do I advise? Extrapolating from the SLEP findings, if an unopened medication, such as my ophthalmologist’s eye drop samples, are stored according to the manufacturer’s recommendations, they should retain their safety and effectiveness for a year or more beyond their expiry date. Opened eye drops, on the other hand, should be discarded after a month or two, not necessarily because of a decrease in potency, but because of concern over bacterial contamination , especially at room temperature.
As for the majority of opened prescriptions and over the counter medications, such as aspirin, Tylenol, antibiotic pills or capsules, blood pressure pills, antihistamines and acid blockers, it is very likely that they, too, will remain safe and effective for months or even years beyond their expiry date if stored properly in a closed container.
However, there is one important exception: if any drug falls into the category of “lifesaving”, its expiry date should be heeded irrespective of any potential for a longer shelf life. In serious disease situations, no one should take a chance with the effectiveness of their medication!