Stick with what works, H O O D. Have you tried seroquel? Zyprexa is known to be a pretty harsh drug with lots of side effects, perhaps seroquel would work similarly.
I went off and on and off dilaudid so many times in the last year - I finally got my doctor to start tapering me down, and although I get less of it this time, I still get about a hundred 8s. I know that sounds rediculous, but shit, the more you got, the more the you use.
Tripman, have you considered s lumbar sympathetic block? An injection which blocks the nerve impulses from sending pain signals, and also reduces inflamation and swelling. Just tell your doctor, very up front, that you cannot go on like this and need to reevaluate your treatments.