What I used to do for my extreme shoulder pain was to make a Tincture of canibis, which is how early medicine was made.
http://en.wikipedia.org/wiki/Tincture
You take an ounce of herb and you put it a jar and cover it with grain alcohol. Store it in a cool dark place for a couple months, the alcohol leaches the THC out of the canibis. Put a few drops in a cup of tea and no more pain. A nice buzz is a side affect I could live with.
Now I have a script for Marinol, legal THC pills. I found Marinol on google, talked to my doc and now I have bottles of the stuff.
http://www.marinol.com/