Our top recommendation is to keep them in a locked med box. Even if your 14-year old jimmies the lock, you now have a springboard to have a discussion because you know that they've taken something from it.
In lots of cases, do you really pill count if you have medication? Say you had a sore back, and you don't use the medication all the time—you usually keep it in your golf bag when you go golfing and just take it then. Do you really know if you have 42 pills left or only 38? Did those other four pills go out with your kids on Saturday night when they went to a salad party? Do you know what a salad party is? It's where your kids will take legally prescribed medications, in most cases from your medicine chest. Their entrée into the party that night is to take things out of your medicine chest, have a pocketful of pills, then put them into a big salad bowl when they get to the party. They just take a handful whenever it's time and ingest whatever they get. They don't even know what they're getting because it's life on ground level.