 There's a good chance that you have some old prescription drugs hanging out somewhere around the house. Most of us do. And as Herb Weissbaum reports, a contributing editor at Checkbook.org, this can be a problem. Americans take a lot of prescription drugs, and we don't always use all of them. As a result, billions of unused doses end up stashed in medicine cabinets or kitchen drawers. A recent survey found that the average adult in this country is hanging on to four leftover medications. Three of them expired.