When I was a little kid, I had pretty bad insomnia (and I still do). My doctor would often prescribe a big ass bottle of promethazine (codeine syrup). He would always give me the purple shit too, which is by far the best tasting type of codeine. I don't think he knew (or cared) that I was starting to develop a dependancy on it. Years later I try some "lean", which is purple codeine mixed with sprite. Usually it slowly knocks people out and puts them to sleep (hence the name "lean"). I haven't had any in a while, and honestly, I think I'm better off without it.