My wife is always complaining to me that she has to take inventory of the drug safe. Some pharmacies are moving to RFID tagging, which should help on inventory. The problem is, with controlled substances, you have to count every pill. If you RFID tag bottles, and some is stealing the pills, then doing inventory with an RFID reader will not help.
The difficulty is that patients swallow pills. So if you wanted to actually RFID tag every pill, you would need to have edible RFID tags. Not that you would have to be able to digest them, necessarily. You just need to be able to excrete them safely. This fact gave me a splendid idea for the slogan of the company that ever develops such edible RFID tags.
Edible RFIDs
They help you keep track of your shit.