We have all had it happen. You have a splitting headache or a muscle ache, go into your bathroom for an over-the-counter (OTC) medication - only to find that it has expired. One of the most common questions I get from friends and family is, “Is it safe to take an expired medication?” The answer on that largely depends, and that is precisely the problem.
Pharmacy uses multiple expiration dates, which can make it very confusing to someone in need of a medication. Prescription Expiration Dates are the date when the actual prescriber’s order expires. This means that a prescription can be filled or refilled after that date and is regulatory in nature. Drug Product Expiration Date, on the other hand, is the date in which the drug product actually expires and is based on scientific information regarding drug stability. For the purposes of this article we are focusing on the expiration date of the drug product, not the Rx.
Expiration dates are required by the FDA to be placed on any over-the-counter or prescription drug. The purpose is to set a date that the products strength, quality, purity, and safety can be assured when stored properly. This date is calculated based on laboratory and quality testing by the FDA and the manufacturer when a drug is approved or when petitioned for an extended date by the manufacturer. This means that a drug may be safe and effective after that date, but it cannot be guaranteed any longer.
Most commonly, after a drug passes its expiration date, it begins to degrade resulting in decreased potency and therefore decreased benefit of the drug. While an OTC analgesic that provides suboptimal strength may still be enough to “work”, the same may not be true for other medications. For example, transplant patients who require very specific dosing of a medication may be at risk for side effects if taking an expired medication.
Alternatively, after an expiration date, the drug may degrade into toxic substances that are downright dangerous to take. The classic example of this is the antibiotic Tetracycline, which has been shown to degrade into a toxic substance if taken beyond its expiration date.
Overall when using medicine, the user should have some guarantee that they are using what has been prescribed or recommended for maximum benefit without needless side effects. Because medicine often relies on exact measurements and calculations to optimize a patient’s dose, when there are questions patients are told to err on the side of caution.
The only way to guarantee this is to take medication only when “in date” and stored correctly. After that date, it is really anybody’s best guess if it going to work and be safe. Because of this uncertainty, I, along with other health care practitioners, recommend not taking something expired.