It is a function of over all health. He just does not feel good.
Maybe like me he has been so big, so long that he has
forgotten what feeling good feels like. It is not just the meds,
but that is a part of it, it is the reason for the meds. I am
sure if he could will himself to feel good he would, but it just
doesn't work like that.
Sorry, can't give you any real advice, only say the more
I lose and move around the better I feel.