The FDA says that people are taking anti-diarrheal medicine in order to get high.
It is because the pills contain loperamide. Users are taking up to 300 pills per day. It is a cheap way to get high because 400 pills only cost $10.
The FDA is working with manufacturers to use blister packs or other single-dose packaging to limit the number of doses in a package.
Doctors say that such a high dose can cause heart problems and is possibly deadly.
