Zytiga was the first of my chemo treatments, and it was started while I was in the hospital in January of 2012 with kidney failure (caused by the PCa). I did stay on the Zytiga for 5-months with, unfortunately, just a waslight increasse of PSA that was steady over the 5-months.
I had started Lupron in late 2010/early 2011 .... and I havee been on Lupron ever since .... 6-month (45ml) shots. I did not notice any kind of spike while I was on the Zytiga. My SE's were moderately light - except it totally ruined my appatite - lost close to 50-pounds - and 15-pounds of it was too much!!!
Wish you luck. Everyone seems to react differently to each med. My latest (4th chemo type) is Jevtana, and I have started a thread about my "Journey with Jevtana" .... since so little info is available for that.
Initial Dx of PCa in 2003/2004
Radiation (5x5wks) & Brachytherapy (96 seeds) in 2004
Low PSA for 6-years then Casodex briefly
Lupron from 2011 to current
Zytiga 2012 (5-months) - PSA increase
Prednisone & Xgeva from 2012
Taxotere - August 2012 (30-weeks) - PSA from 54+ to 12+
No chemo (8-wks) - PSA to over 23
Xtandi - June to Aug - 2013 - PSA increase
Jevtana + Lexapro - from October 2013