I can't add much more to what unyquity and scott760 have told you. When I originally became ill I was prescribed Amytrip to keep me at work but as the effects wore off the doctor kept increasing the dose, then added painkillers and in the end I was drugged up to the eyeballs with antidepressants and morphine. This cocktail doesn't allow one to think straight but one day I decided to dump the lot. Guess what? I felt better taking nothing. (After I got through the withdrawl)
Then I had a stoke of luck and was sent on a 4 week residential pain management course. On this course I was told has to manage the pain through relaxation, eating well, graded exercise, and good psychology. They told me on this course that Amytrip cause the gallbladder to fail and that it's better not to take drugs if you manage it. I later read on a drug information sheet that this could be a side effect to long term use.
I liver flushed very enthusiastically and now my insides are just fine. I still have the chronic pain but that's all. Life is manageable even when I have a flare-up.