My old mate, aged 87, has had Prostap quarterly injections for five years, and Bicalutamide for the last two years until it stopped working. He has had no side-effects whatsoever from the HT. And in fact no PCa symptoms either!
They have changed his tablets to a different HT, which, again he has no problem with, and his PSA is declining.
The specialist did say Bicalutamide usually only works for 12-18 months, so my mate was lucky to get two years out of it. They will eventually switch him to more advanced (and much more expensive drugs).
I hope your Dad fares as well.
Cheers, John.