You didn't post your brothers statistics with PCa, he maybe should have had casodex prior to the LHRH type drug (the shrinker-usually used), if he experienced what is called 'flare' as 'T' levels surge before your system shuts down T-testostorone production to slow down PCa. This flare gig can cause additional side effects and make you feel awful....could have been prevented by taking casodex prior for 14 days (this is in Dr. Strums book and other books). Maybe your doc is under schooled, this happens often from average docs, the better docs use casodex prior to prevent flare and possible reactions that can happen. We just had another man on here experience the same horrible side effects, it is preventable (most likely), so how ridiculous for such to happen. Best to you and he should feel better within days or weeks for sure. Maybe what Don and Fairwind mentioned also combined caused such, but I think the intial flare is the real culprit.
I started with Zoladex, later added casodex and proscar to make it ADT3...was not alot of fun, but never had nausea and real sickness in the mix. Just the usual suspects of muscle/strenght loss, fatigue, fat-gain, hot flashes and heavy sweats randomly, maybe a little brain loss (LOL-memory that is).