Fortunately I wasn’t on 100mg of prednisone for long, but weening off takes awhile. Your husband has some of the classic side effects. He can try some over-the-counter sleep aids on occasion. I’ve tried Lunesta and Ambian, but start with the over-the-counter first. Watch what he eats, I gained weight too, about 30 lbs. My doctor put me on “Akins” and it helped. I took an antidepressant for awhile (yes, my doctor was an Internist). That was hard to come off of. I didn’t think I was that irritable, but my family told me otherwise. The ‘Moon face’ should go away, at least mine did. Prednisone take some time to ‘kick in’.