Hello Chinki ....
I started the Xtandi about the same time as your Dad ... 13-days ago for me to be (as of today). My temperature was taken on Saturday (the 10th day of Xtandi), and it was at just over 98. And it was taken last Tuesday (the 6th day), and it was fine then too.
My start of Xtandi, however, was after two months of no chemo of any type. In my case, the taxotere was stopped in April ... and the only cancer-related meds taken during those 2-months were the Lupron (6-month) injection, the Xgeva (monthly injection) and one 5-mg Predisone daily along with a 400-mg calcium + vitamin D capsule daily.
I'm glad to hear that his back pain is better - at least that's a positive! So far, and I emphasize the "so far", my se's have been limited to some diareaha and fairly constant tiring - but the tiring could be from the Lupron.
My onco has me coming in this Friday (the 16th day of Xtandi) for a toxicity test (first one I have had to my knowledge) and for a PSA check. So ... some "pins and needles" for the next few days for me. I hope your Dad's apatite gets better ... mine was next to nothing after my 4th month of Zytiga last Summer. I introduced myself to "Ben and Jerry", and either the ice cream ... or a cycle in the med se's got me out of the negative apatite.
Best wishes to you and your Dad ...............