Every primary care physician occasionally encounters questions similar to the following. “I just found some of my blood pressure medicines.  The container fell behind the couch a year ago.  The expiration date was last month.  Can I still use them?” or “I know you just prescribed amoxicillin for my sore throat, but I just found some amoxicillin in my cupboard that I bought during the Nixon administration.  Can I take that?” The bigger question is, what happens to medications after they expir...