I don't know much about meds at all but I was thinking the same as Joan- maybe alternative pain control, or an added med to work with what is helping already?

This is just off the top of my head - but-
Has anyone tried hypnosis for RSD pain?
Or that EFT {Emotional Freedom Techniques}
http://www.emofree.com/downloadeftmanual.asp
free pdf download that describes how to do it.

That EFT stuff sounds really wacky - but I used it for my severe RSI in 99 and amazingly it did work. I was trying from a skeptical viewpoint - so I was even more surprised when it worked.
I didn't even do any of the chanting - just the tapping parts.
So perhaps it might lessen the pain?
It's supposed to work for many other issues too - fear, pain, habits, really anything you want to change so they claim.