http://en.wikipedia.org/wiki/Fen-phen had a body count before it was banned. Such cases are rare, but that means the system is doing at least part of its job.
If you want to cut down the number of people taking dangerous drugs, ban doctors from prescribing non FDA-approved drugs and ban companies from marketing them. However, I have only contempt for people who want to put their fellow citizens in jail for making their own medical decisions.