• We did decide that every addict in this film, Warning: This Drug May Kill You, would be someone who started out with a prescription for an opioid from a doctor. The story that hadn't been told is that the vast majority - somewhere around 80 percent - of current heroin users began with an addiction to prescription opioids. So as much as people might want to look at this and say, 'Oh this is really a heroin problem,' yes, it is a heroin problem, and no one is saying differently, but it starts more often than not with a prescription.