Disclaimer: Use at your own risk. I'm not a doctor. And I don't know if it would be best in a FAK, but...

I had a bung shoulder that wouldn't stop hurting. Nobody could figure it out and nothing helped. And I struggled with it for over a year.

During that time, I hurt my back - and the doctor gave me Celebrex (among other things). The back problem went away - and so did the shoulder problem.

It was the only thing that helped me. ('course I might die tomorrow - but at least my shoulder won't be hurting)

FWIW - YMMV.