HI Oakfern,
If you're doing OK on Prostap, then personally, I would say stick with it.
I have been in the same position as you.
Over the years, Zoladex did well for me, then after I'd taken a 'hormone holiday' for a few years and it became time to get back on treatment due to rising PSA, my onco asked what I'd like to have.
I opted for Casodesx 150 - and although it got my PSA right down to <0.1 quickly, I had to quit after seven months.
The side effects of very sore man-boobs, and having to take Tamoxifen to help the problem, put me right off it.
But worse was to come. Within weeks of stopping Casodex, my PSA rose at a speed I'd never seen before - from 0.1 to 12.0 in 12 weeks. At the same time, my testosterone went through the roof. I fully believe Casodex caused that spurt.
I then chose Prostap. which rescued me, getting PSA down fast, and then returned to my old faithful Zoladex.
Last November I took another break from HT and there was no sudden surge in PSA..
Over the past year it has just creeped up very slowly, and I hope to get perhaps another12 months or even more before it reaches 10.0 and I need to return to HT.
I know we are all different, but Casodex is certainly not for me, and I've seen very similar complaints about it from our friends here on the forums.
All the best,
George