Medication Safety

Sonya Collins

Most drugs have a labeled shelf life of about one to five years. Research shows, however, that these drugs are still safe and effective for decades beyond their expiration date. But should that change the way pharmacists counsel their patients? Probably not.

“Pharmacists would be the most likely group to use a medication past its expiration because they know that the science on which expiration dates are based is limited,” said Randy Hatton, PharmD, a clinical professor at University of Florida College of Pharmacy. “But it would put a pharmacist in a difficult position to counsel patients to use them after the expiration date even though the odds of harm are overwhelmingly low.”

Do expired meds work?

A drug’s expiration date indicates the date until which the drug manufacturer guarantees the medication will remain potent when stored properly.

“But it may remain potent after that,” said Dan Sheridan, RPh, a medication safety pharmacist at OhioHealth. “Research shows some medications remain potent long after that.”

The Department of Defense Shelf-Life Extension Program routinely tests the stability of drugs in its national stockpile in order to avoid replacing them more often than necessary. Initial tests of more than 100 medications in the federally stockpiled medical material found that 90% were still potent 15 years after their expiration date.

A 2017 study in Annals of Internal Medicine tested the potency of 40 EpiPens that were 50 months past their expiration and had been stored improperly. Almost half (24) of the EpiPens were still potent.

As described in a 2012 research letter in JAMA Internal Medicine, researchers tested the potency of 8 medications (with 15 different active ingredients) found in their original packaging in a retail pharmacy. Their expiration dates ranged from 28 to 40 years prior to testing. Eighty-six percent of the medications were still at least 90% potent—the generally recognized minimum acceptable potency.

Nevertheless, it’s rare to see expiration dates extended on drugs for private consumer use. An exception would be when a drug is in short supply because, for example, the manufacturer has discontinued it. In this case, FDA may allow for extensions in order for the public to continue to access the drug until the supply has been exhausted.

“They stopped making coral snake antivenom because, fortunately, there’s not a big market for it,” Hatton said. “And every year, like clockwork, they extend the expiration date another year.”

Other than that, Hatton said, “drug makers have absolutely no financial incentive to extend their expiration dates.”

Are expired meds harmful?

Most likely, the greatest risk of using an expired medication is that nothing happens at all. The only real risk is that the drug is no longer potent.

The last recorded adverse event caused by taking an expired medication was reported in JAMA in 1963 when three patients—one adult and two adolescents—developed reversible Fanconi syndrome after taking expired tetracycline.

“It wasn’t in the same kind of packaging we have today, and it formed a couple of degradation products that were toxic to the patients,” Hatton said.

While most medications seem to remain potent and safe long after their expiration date, Sheridan said, “there are a few exceptions. Eye drops, antibody powders, and nitroglycerin shouldn’t be used past their expiration dates.” 

Counseling patients on expired meds

Pharmacists should continue to counsel patients not to use medications past their expiration date when they dispense these medications. However, if a concerned patient calls the pharmacy after taking an expired medication, in the overwhelming number of cases, pharmacists can assure patients that there’s nothing to worry about.

“The published evidence shows that drugs are stable long beyond their expiration dates,” Hatton said, “and that it would be highly unlikely that any harm would come from them.” ■