I (me and mama) recently had the [misfortune] of using prescribed antibiotics for different reasons. She had to use all of hers for upcoming surgery. I, on the other hand, did not need all of mine and ended up with about a two day supply left over. Well, 2 days isn't much but what if it was all you had? I took a gallon zip-lock bag, inserted the leftovers pill bottle, went to Drugs.com and printed out the fact sheet for the AB and included it in the zip-lock. Used a Sharpie and wrote big on the outside "Antibiotics". If the medicine is still usable after two years, it is worth the trouble. I'm sure this system would work well with other leftover medicine; you just have to be ever-vigilant about dates and safety. I guess in a SHTF situation you can't be choosey.