Hey Jane,
Although I agree this is not a good situation, I think to some degree it may be understandable.

I've never taken this combo but I'm still taking Orogovyx. Other things aside, he may be tired because of the lack of sleep. A good night sleep can be very elusive when you're experiencing 2-4 hot flashes at night. I know that it is for me. I don't have any experience with the Zytiga meds.

My response to this has been to stay very active with the thought that my body will take the sleep that it needs when it needs it. This is pretty much what happens. I don't get the sleep I may like to have, but I get what I need (hearing a Rolling Stones song suddenly) Having said that, if I'm home, after a workout in the afternoon, a nap is just what the dr ordered. (literally)

He may also be experience a mind set of "this is the rest of my life" in regards to the medication and side effects, that's tough for anyone to be able to push back in their minds and concentrate on the good things available to them.

My only suggestion is to try to accentuate that the drugs are working without being too pushy, accentuate the positive as it were. Also if it's an option, the opportunity presents itself, I might consider telling his primary medical care person (surgeon, urologist ?) of how you see the situation, privately, and see if he / she can offer any assistance / advice. After all, the disease is having an effect on the entire family.

Best of Luck to you and him!