All of those things have non-violent uses much more important than their violent ones. Cigarettes are a better analogy--I think there is definitely a case to be made that is a violent activity.
Unless you can personally claim ownership of those people, among other things you're claiming ownership* of, there is no aggression (initiation of violence) taken upon your person or things when someone is destroying their life.
If you can personally claim ownership of those people, and society as a whole, then you are correct and the selling of the drugs would be an act of aggression towards yourself.
* The act of withholding something from others.