All prescription and over-the-counter medications have expiration dates printed on their labels. I suppose this is partly because many of these items lose their effectiveness over time and partly because the drug manufacturers would like you to go out and buy new stuff rather than continue to use the old stuff.
So, even if the stuff does lose some effectiveness, it’s one thing to take old medication that’s only 70% or 50% as effective as it once was, but it’s a completely different story to take something that was once curative but has turned toxic. The question comes to this: what medications on the market, OTC or prescription, can become harmful over time and would be dangerous if used well past the expiration date?
Medicines have expiration dates because it’s the law. They determine the date through stability testing, which is expensive, so they don’t test any longer than they have to. The Degradation products of a drug may or may not be toxic, and in most cases no one has attempted to find out. The limits for drug potency are normally 90% - 110% of label claim.
I have found an amazing coincidence in all prescription medication I have ever received. It seems that no matter when the pharmacist purchased the medicine, and no matter what the expected shelf life of said medicine, by some miracle the expiration date on the label is always exactly one year from the date I purchased it.
I’d say the odds are pretty close to 100%. It seems the act of pouring the stuff from their big bottle to your little bottle automatically shortens the drug’s life expectancy to one year from the date of pouring.
Pharmaceutical technology is more sophisticated than you thought.
But seriously folks, I have read that aspirin and acetaminophen don’t degrade into anything harmful. I was just wondering if there was anything that did, but as Nametag explains, this isn’t part of their testing.
From recent events I guess we still have to worry about whether a lot of the stuff out there is harmful even during its useful life.
I used to work in a lab where, among other things, we determined expiration dates for supplements. Stability studies merely looked at the concentration of the active ingredients listed on the label. The expiration date was when the active ingredient was no longer present to within a certain percentage of the label claim. No one looked to see what it might have decayed into.
Now, keep in mind that this is an industry that’s not regulated by the FDA. The requirements for pharmaceutical companies are different.
Once upon a time, I remember reading a print article that said that most drugs don’t degrade into anything harmful, but that a few did, which it listed. I wish I could remember more. I think one was a prescription topical cream of some kind.
The tetracycline family of antibiotics can turn deadly with age.
Most other medicines do not degrade into anything harmful, and many retain their effectiveness for their stated purpose for long after the expiration date.
Check with your pharmacist for details about your specific medicines.
Perhaps I should amplify a little on my reply. Stability testing includes a number of tests, each measuring some aspect of product performance. In addition to potency, a drug dosage form must remain physically and chemically capable of delivering the drug – pills must remain in one piece and yet dissolve in the proper time and conditions, injectables must remain sterile and particle-free, creams must not separate, etc. The amount of drug substance present is measured using a “stability-indicating method” – i.e., one that measures the amounts of the degradation products as well as the drug substance. There are FDA and international guidelines for how much degradation can occur before these products must be identifed and characterized. If there’s a particular reason to believe that there’s an unusual hazard (high concentration, high probability of toxicity based on the chemistry of the drug), the company may elect (or be required) to conduct toxicology studies in animals, either by isolating the degradant or by administering degraded drug product.