I think GPs prescribe Amitryptiline because it targets anxiety very well, and anxiety from dealing with constant pain only makes the pain worse - it is not regarded as a pain killer as such. But if it helps keep anxiety under control, which it certainly does for me, then the stress that is generated by dealing with pain is lessened.

Thankyou,im.very.scared.last.night.my.arms.legs.so.stiff.couldent.move.them.without.great.effort...and.couldent.turn.over..What.mediation.is.there.for.this?

I haven't found pain reduction with meds... The only thing I can say is that the reduced my anxiety.