The sleep thing is hard...very hard and the main problem I think. He has to take sleeping pills every night and because of that they're becoming less and less effective. Currently taking Stilnox every night but only gives him 3 hours tops then he's awake again.
I was prescribed stilnox once. It was designed as a short acting sleeping pill (2-3 hours) that you can wake up from quite quickly and be alert. It's good for if you have trouble getting to sleep but not so good if you have trouble staying asleep. Maybe if he changes up his script to a different, longer lasting sleeping pill he might sleep longer. Also side affects can include paranoia/delusions/altered thought patterns.

The heroin might be a better option. Yes, it is addictive but at the moment I think that sleep and effective pain releif outweigh the concerns about addiction and ironically enough it is a more natural substance than the stilnox.