My father-n-law is suffering with very bad neck and back pain. He has had his spine and neck fused and still complains about pain, there are days where he wont even get of beg because of it. I met someone once that had a back injury and his doctor prescribed him methidone and he feels like he has his life back free of pain. Can this be a good idea for my father-n-law. Also he is a diabetic with nuerapothy and has a heart condition.