Have you ever looked into your medicine cabinet and cleared it of all expired drugs? You may want to think twice before doing that. A new laboratory analysis of eight prescription drugs that expired between 28 and 40 years ago has found that most have remained just as potent as they were on the day they were made. Overall, the eight drugs included 14 different active ingredients, including aspirin, codeine and hydrocodone. In 86% of cases, the study found, the amount of active ingredient present in the drugs was at least 90% of the amount indicated on the label. According to the Food and Drug Administration (FDA) that falls within the range deemed acceptable by the Food and Drug Administration. The FDA allows “reasonable variation” in the strength of any given batch of prescription drugs, generally requiring that drugs contain between 90% and 110% of the stated active ingredient.
Although consistently taking depleted prescription drugs could certainly cause complications, expired drugs are generally safe. In the medical literature there is only one example of an expired drug that became toxic, and that was an isolated incident, says Cantrell, the director of the San Diego division of the California Poison Control System.
But don’t go dumpster diving for your expired drugs just yet. For starters, some of the drugs tested are no longer widely used, and it’s not clear that the results would be the same for different drugs, or for similar drugs stored in different conditions, says Mohammad Nutan, an associate professor of pharmaceutical sciences at the Texas A&M Health Science Center, in Kingsville.
Still, Cantrell and his colleagues say, the findings suggest that the expiration dates of some drugs could be safely extended. The FDA, in fact, has already done so for certain medications in short supply, including anti-venoms for the Eastern Coral snake and the Black Widow spider, Cantrell notes. “Perhaps expiration dating of medications needs to be revisited,” he says.