You grab an aspirin or uncover a prescription drug that used to soothe your back pain -- and then notice the expiration date is long past.
Should you use the medicine, or not?
Some pharmaceutical experts are fond of pointing to a study done for the U.S. Army that found that many drugs were still usable nearly five years after the expiration date. But other experts say it isn't worth the risk and you should toss old drugs.
The Army study was presented at the 2002 U.S. Food and Drug Administration science forum. The review examined 96 different drugs, and included 1,122 lots in all, and found that 84 percent remained stable 57 months beyond the expiration date.
But even the researchers, in their report, said the additional stability period is "highly variable," depending on the drug.
"I would take expiration dates seriously," said Cynthia LaCivita, a pharmacist and director of clinical standards and quality for the American Society of Health-System Pharmacists, in Bethesda, Md.
"The longer you go beyond the expiration date, the more question there is about the activity of the drug," LaCivita added. "There are some other studies that show over time some of these drugs are degraded."
LaCivita recalled a recent study that found that liquid antibiotics, often prescribed for children's ear infections and meant to be stored no more than 14 days under refrigeration, began to lose some therapeutic value after the 14 days.
Manufacturers calculate expiration dates for drugs after testing the product to see how fast it degrades, she said.
LaCivita noted that the study conducted for the U.S. Army "looked at drugs in their original, unopened container. That is not usually how an individual would store a drug."
Most consumers don't store medicines in optimal conditions, making it even more crucial to pay attention to the expiration date, said Rachel Bongiorno, a pharmacist and director of the University of Maryland Drug Information Service. "To be on the safe side, I would never recommend anyone take medication past the expiration date."
If medicines, such as aspirin, look sticky or crumbled, it's a sure sign to toss them, said LaCivita.
"The biggest problem is, it won't be as effective," Bongiorno said.
But there are other reasons not to take old medicine -- like that back pain drug that worked years ago. "You may start a new medicine that may interact with the old one," Bongiorno said. "You may have another disease that could require a dose reduction" of the previous medicine.
LaCivita recommends people go through their medicine cabinet once a year and throw out expired drugs. She suspects that few people do this, based on the impromptu searches she carries out when she visits family members.
"I would have to say, based on my family members, I can always find medicines that are not just days but years out of date." And they're familiar with her cabinet-searching routine. "You would think they would listen to me," she said with a laugh.
If you use medicine before its expiration date, you can be sure you're getting the medicine's best benefit, both experts said.
To learn more about medication safety, visit the University of Michigan Health System Patient Safety Toolkit.