That goes for over-the-counter drugs, as well as prescription meds.Check the expiration date before even buying those pain relievers or allergy tablets, some pharmacists advise — the same way you check your milk. "Once the expiration date has passed," Bernstein says, "there is no guarantee that the medicine will be safe and effective." Of course, even new drugs can quickly lose potency if they're not stored properly.
This is true one of the breakdown products of aspirin is acetic acid (vinegar).
Even the slightest decomposition of aspirin will give this smell, even though the aspirin may still be 99 % pure.
The general rule, says pharmacist Mike Fossler, with the American College of Clinical Pharmacology, is that once a drug is degraded by 10 percent it has reached "the end of its useful life." If you take it months or even years past the expiration date, it's unlikely to do you any harm, he says; it just might not do you much good.
That may not be a big deal if you're treating a headache, but if you're fighting a bacterial infection with antibiotics like amoxicillin or ciprofloxacin, for example, using less than fully potent drugs could fail to treat the infection and lead to more serious illness.
However, while I would toss out old antibiotics, I would have no concern with taking a ten-year old Lipitor pill.
Most of us have reached for a painkiller, at one time or another, only to discover the date on the label shows it has expired. It turns out that date stamped on the label actually means a lot.
That date is the date until which the product manufacturer guarantees the full safety and potency of the drug.
The date does necessarily mean that the drug is unstable after the expiration date; it just means that the product will be for sure be stable until the expiration date. But drug expiration dates are much longer because drugs don’t spoil.
Perhaps the most helpful information about this comes from a former colleague of Dr.