My treatment was RT & Zoladex for 3 yrs, (starting Dec 2015)as part of trial I had enzalutimide, abiraterone & prednisolone, included for 2 of those years.
I cannot comment directly about abiraterone/prednisolone. I had most of the expected side effects of this treatment, caused obviously by combination of all of them.
One side effect that was directed at prednisolone was very sore Achilles tendons. They were extremely sore at times to a point where if I even thought about touching them they hurt. I continued trying to at least walk for hour each day, on one occasion I was about a mile from home when my achilles' became nearly unbearably painful, it took over an hour to walk that mile and I felt quite sorry for myself (obviously I was too 'manly' to phone someone to pick me up).
Apparently the prednisolone can shorten/thicken the Achilles tendons temporarily, I saw a physio a couple of times who advised to stretch the tendons etc, which was logical. Once I'd learned it was an 'expected' side effect I felt happier anyway, I just wasn't aware.
May have been combination of enzalutide/abiraterone but my BP increased a fair bit and I was prescribed couple of BP tablets, which I still take.I
Peter