Expired Medications: Are They Effective?

I will be the first to admit that my bathroom closet contains a small pharmacy consisting of expired medications.  From left-over antibiotics (you know you have some too) to a few 'tabs' that remain unused from my husband's root canal, I feel like at some point over the next few years I may need to pop some pills to treat a self-diagnosed UTI or broken pinky finger.  Yes, I know, I am as bad as my patients.  But are these expired medications littering my cupboards safe and effective?

Recents studies show that prescription medications remain potent and safe for much longer than expected.  The Shelf Life Extension Program (SLEP), a joint effort between the U.S. Department of Defense and the Food and Drug Administration which aims to reduce the cost to the military of maintaining stockpiles of certain medications, released a study discussing the efficacy of expired medications.  The study analyzed medications which had expired 28 to 40 years ago.  Typically, expirations dates for medications are set anywhere from 12 to 60 months after production. 

The FDA maintains that for medications to be deemed safe and effective, they must contain their active ingredients in a concentration between 90% and 110% of the amount indicated on the medication label.  12 of the 14 medications analyzed in this recent study maintained a potency of 90% or greater for 336 months (28 years) or longer.  Eight of the medications maintained their potency for an astonishing 480 months (40 years!).  Which medications did not maintain their efficacy for at least 28 years?  Aspirin and amphetamine fell below the 90% potency guideline.  

Based on these results, the Self-Life Extension Program has extended the expiration date of most drugs tested from anywhere between 66 and 278 months (5.5 to 23 years).  Looks like that 7 year-old bottle of codeine-containing cough syrup I have been guarding will still do the trick if I come down with a nasty case of the flu!