My wife and I have this argument (she calls it a "discussion") several times a year. I discover some perfectly good food of uncertain age in the refrigerator. She wants to throw it away – better safe than sorry! I say if the color looks right, it smells like food, and tastes alright, we should eat it. And with that another perfectly good pasta dish (or was that chicken?) is tossed out.
We have similar discussions about expired medications. I'd heard medications were often safe and effective well past their expiration date; she's ready to throw them out if they're even close to the date on the bottle.
So, who is right?
The U.S. Air Force started a study in 1985 (described here) and later extended it to other military services in the early 1990s. The military had gathered a stockpile of medications worth more than a billion dollars that were close to or past their expiration dates. No one wanted to throw away expensive medications that might still be safe and effective. So the drugs were extensively tested with oversight by the U.S. Food and Drug Administration (FDA).
The verdict? Most medications were still good nearly 3 years past their expiration dates.
So, I was right!
Well, sort of. Before ignoring expiration dates on medications, there are a few caveats to keep in mind:
- These tests of drug stability were in the mid-1980s and early 1990s. It's likely that newer medications have not been tested as well (or at all).
- Only about 100 drugs were tested. And many were drugs that are rarely used by people who are not in the military such as antidotes to chemical poisoning and antibiotics for malaria. However, a more recent study with other drugs came to similar conclusions as did a recent review of prior research.
- Some drugs did fail the stability test. Studies of liquid antibiotics, aspirin, nitroglycerin and insulin, for example, have found signs of physical decay. So, for these it's probably best not to use them past their manufacturer's expiration dates. Mefloquine, an antibiotic to prevent or treat malaria, and Epi-pens (injections of adrenaline for severe allergic reactions) also held up poorly past their expiration dates.
- The details matter. It may be fine to take an allergy medication that's a month past its expiration date. But there is some risk in taking a heart rhythm medication that, if ineffective, could lead to an unstable and dangerous heart problem. And a medication that's a month past its expiration date may be potent while one that's 5 years past is not.
- Medications kept in a cool, dry place are likely to last longer than those kept in a hot, damp location.
How did we get these expiration dates anyway?
Since 1979, the FDA has required drug makers to give each medication produced an expiration date. And there must be some testing to come up with the duration.
Why couldn't the expiration dates extend farther into the future? A cynical view (and one that may be right!) is that drug companies establish expiration dates to encourage us to replace our older medications (even if they are still good). The more we throw out, the more we'll need to buy to replace them.
Drug makers say that extensive testing of drug stability over prolonged periods of time would be ideal but is too expensive, especially considering that people may keep drugs in so many different environments (for example, hot, cold, humid, dry, etc.). Also, improvements in drug manufacturing and changes in drug information over time would require repeated "longevity" testing that would be impractical. Better, they say, to pick a shorter period of time for which there is confidence a drug will stay stable and stick with that.
That might be acceptable if it weren't for the pharmacist who may reduce the expiration to one year from when the prescription is written! Some states require pharmacists to do this. This came from a 1985 recommendation from the U.S. Pharmacopeia, a not-for-profit group that establishes standards for drug makers.
The logic is that when a drug is taken out of its original container and put in a pharmacy canister, moisture and air can degrade the pills or capsules. In addition, a patient's condition may change, new drugs may become available (so that the old drug is no longer the best option), or new information may become available (such as potential interactions with other drugs). So, limiting the prescription to a year from when it's originally filled adds an extra level of safety, requiring the doctor to review whether continuing with the old medication beyond one year is still a good idea.
Even with the best of intentions, this conservative standard makes it even more likely that enormous amounts of perfectly good medications will be thrown away in this country each year.
The Bottom Line
The next time my wife starts throwing out expired medicine, I'll remind her that in the military study I mentioned above, the savings amounted to more than $260 million by keeping expired medications. We may not save that much. And we don't have the FDA to test and oversee extensions on our medicines' expiration dates. But there is a fair amount of evidence that medications stored properly, appear intact and are not one of the exceptions mentioned above, are likely to be safe to take.
For many common conditions, such as allergies, headaches or back pain, I'm willing to take the risk of applying my own, modest extension to the expiration date.
It's too bad that the mystery leftovers in the fridge don't come with an expiration date. But even if they did, I'd be tempted to stretch those, too.
— Robert H. Shmerling, MD