Pharmaceutical drugs, both prescription and over-the-counter come with an expiration date. This manufacturer expiration date applies to unopened containers and many patients think they should discard expired meds or that it will be dangerous to take them. But do they really need to toss the "old" one and buy something new? Is there a problem with safety? What about the efficacy...will it still be potent?
The Medical Letter on Drugs and Therapeutic, a well respected and non-biased publication, looked at shelf life extension and the stability of expired medications. They showed that all drugs they tested were stable for a year past the expiration date, and most drugs stored in unopened original containers were fine for 66 months. (that's 5 years!) One drug, theophylline retained 90% of potency 30 years past its expiration date.
Solutions and suspensions are less stable than solid medications. Epi-Pen auto-injectors may lose potency after the expiration date so that is one that should be replaced if expired.
So the answer to the above questions about using expired medications are here:
1. Is there a problem with safety? No. There are no reports of toxicity.
2. Will it still be potent? If the medication is in a cool, dry place in the original container, it is probably 90-100% potent and good for at least a year after expiration and maybe even up to 5 years later. Exceptions would be Epi-Pen, liquid antibiotics and insulin.