Does Medicine Really Expire?

Ever since 1979, the U.S. Food and Drug Administration (FDA) has required that pharmaceutical companies put expiration dates on prescription and over-the-counter medicines.

That doesn't mean your bottle of ibuprofen will go bad in the same way as, say, an expired carton of milk. The date that you see printed on a pill bottle is the date until which the medicine's manufacturer will guarantee the drug's safety and full potency. How long a drug actually remains safe and effective, however, is often a matter of debate.

Besides some medicines like insulin, nitroglycerin and liquid antibiotics, whose active ingredients are known to be less stable over time, many drugs might have a much longer shelf life than their packaging suggests. [Why Do People Get Sick When the Seasons Change?] 

But not everyone knows that, so poison control centers occasionally get calls from people who are concerned because they accidentally took expired medication, said Lee Cantrell, director of the San Diego Division of the California Poison Control System.

"The last time I checked, I haven't seen any peer-reviewed documentation of expired medicine causing any problems in people," Cantrell told Live Science. The effectiveness of medicines, however, may degrade over time, but there are few studies on the issue, he said.

That said, several years ago, Cantrell had a rare opportunity to examine an old stash of drugs — including antihistamines, pain relievers and diet pills — found in the back of a pharmacy.

"We found that those medications, some of them at least 40 years past their manufacture date, still retained full potency," Cantrell said. That study was published in the journal JAMA Internal Medicine in 2012. Cantrell published another study in 2017 showing that EpiPens — the expensive auto-injectors used to treat life-threatening allergic reactions — retained 84 percent of their potency more than four years past their expiration dates, suggesting that in an emergency, an expired EpiPen would be better than nothing.

In Cantrell's view, pharmaceutical companies are the only ones that have the money to do long-term studies on drug's efficacy, "but there's absolutely no financial incentive for them to do it." (When the medicine you need expires, you, or your insurer, pay for more.)

The federal government, however, has a financial incentive to study the shelf life of drugs. The U.S. maintains a stockpile of medicines that could be needed in the case of an emergency like a terrorist attack or a disease outbreak. In 1986, the FDA and the U.S. Department of Defense started the Shelf-Life Extension Program (SLEP) to save on the costs of replacing expired drugs in this stockpile.

A SLEP study in 2006 tested 122 different drugs stored under ideal conditions, and as a result, extended the expiration date of a majority of the drugs in the stockpile by an average of about 4 years. In 2016, SLEP helped save $2.1 billion that would have been spent replacing expired drugs in the stockpile, the Department of Defense reported, according to a ProPublica investigation. Even so, the FDA still strongly warns consumers against taking expired medicine.

"Certain expired medications are at risk of bacterial growth and sub-potent antibiotics can fail to treat infections, leading to more serious illnesses and antibiotic resistance," the agency says on its website. Questions about specific expired medications are best directed toward your pharmacist or doctor.

The FDA also encourages people to bring their unused and expired meds to the National Prescription Drug Take-Back days, hosted by the U.S. Drug Enforcement Administration (DEA), in part to prevent abuse. The White House claims that in 2018 these events "shattered records" with nearly 3.7 million pounds of unused and expired prescription drugs recovered.

But while the Trump administration might see a victory in that high number, others will surely see a massive amount of pharmaceutical waste.

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Originally published on Live Science.