Zytiga and Xtandi

[Dastardly]

I am not tolerating Zytiga well at the moment because of high blood pressure, irregular heartbeat and possible Atrial Fibrillation. I have a clinic meeting coming up shortly and am looking at alternatives so that I can speak to my oncologist with some understanding of the possibilities available.

I guess the first option would be to reduce the dose of Zytiga to 500mg daily to see if I can tolerate that any better. I am loathe to let go of something that I had hoped might keep me going for up to 2 years without giving it a second chance.

I have read conflicting reports about going on to Xtandi after having been on Zytiga. One is that there is no point in going on to another 2nd line treatment if the first one has failed. In this case though, it is me that has failed and not the treatment, so does that make a difference? I have also read that there is a positive result from going on to Xtandi after Zytiga. So, has anybody been in my position and found a definite benefit in taking Xtandi after Zytiga?

My next question is that, assuming I can't tolerate a reduced dose of Zytiga, and there is no discernible benefit in going on to Xtandi, what comes next? My PSA is running at <0.1 at the moment and, I should point out that I live in the UK and my oncologist took me off Zytiga just on 4 weeks ago, so it will be interesting to see what that has done to my PSA when I have my bloods done.

This really is a great site with a level of support and expertise that doesn't exist anywhere else, and I am truly grateful to everybody who contributes.

Take care.

[Tall_Allen]

(1) Try increasing the prednisiolone dose slightly. The high BP may be a signal that you are not taking enough to compensate for your depletion of cortisol in your particular body. In pre-clinical studies, cortisol depletion has been implicated in strokes:

ahajournals.org/doi/10.1161...

(2) Xtandi may induce arrhythmias:

ascopubs.org/doi/full/10.12...

(3) Switching is only problematic if you are already resistant to Zytiga

[Dastardly in reply to Tall_Allen]

Thanks as always T_A.

I did suggest low cortisol levels in a message to my oncologist but have heard nothing back yet. I will certainly get cortisol levels checked at my next bloods to see if anything is going on.

Good news/bad news about Xtandi. Yes, I could change to it as I am not yet resistant to Zytiga. The bad is it will probably make my arrhythmia worse and has the added benefit that I may fall over a lot as well.

Oh well, onwards and upwards.

Many thanks

[Gearhead]

I agree with Tall_Allen's (1) suggestion. If there is a problem with increasing prednisone or if it doesn't seem to reduce your BP, another alternative is to maintain same prednisone dose and add eplerenone (Inspra). Research has shown that eplerenone can be taken with Zytiga instead of prednisone. I take 5 mg/d prednisone + 50 mg/d eplerenone with 1000 mg/d Zytiga. This lowered my BP relative to just 5 mg/d prednisone, bit it's still higher than I would like.

[Dastardly in reply to Gearhead]

Thanks for the response, Gearhead.

I will certainly have words about both prednisolone as well as eplerenone. I have been put on 5mg Amlodipine daily for the high blood pressure, and that seems to be doing the job. What concerns me most at the moment is the arrhythmia and atrial fibrillation but am still waiting for a cardiology appointment. I think that my best option in the meantime is to try a reduced dose of Zytiga and possibly increase the prednisolone.

All the best to you

[Benkaymel]

I am also in the UK. Not sure if you're on the NHS like me. I have a history of high BP and arrhythmias and have been on amlodipine for some years. I started on Xtandi a couple of months ago and have had no problems with SEs except a bit more fatigue. Everyone's different but it's working well for me so far if that's any help.

[Dastardly in reply to Benkaymel]

Thanks for your response Benkaymel.

Yes, I am also on the NHS and struggling a bit because there is so much additional demand for both Prostate cancer and heart ailments as a result of covid.

I was interested in your reaction to Xtandi so far. I have read that it has caused balance problems to a number of patients, resulting in falls. I have osteopenia at the lumbar spine, so that doesn't seem so appealing. Also, if I get any more fatigue on top of that I already have, I may as well stay in bed all day.

Still, it is what it is, and I'm still in the game.

Mamy thanks

[Benkaymel in reply to Dastardly]

I would say my fatigue is only marginally more than it was on just Prostap and regular exercise helps a lot to deal with it anyway. I've not noticed any balance problems as yet though I know they are one of the possible SEs. I do get restless legs at night that sometimes makes it hard to get to sleep - this combined with frequent peeing is probably my biggest problem with the PCa plus meds at present.

[CharlieBC]

I was in your situation. Zytiga worked great for me, lowered my PSA significantly. But my liver enzymes went way out of tolerance. Even cutting Zytiga dose in half, it affected my liver. Switched to XTANDI in August 2021. It worked and continues to work well keeping my PSA down. I think because I wasn't on Zytiga long enough for my body to develop a tolerance to it (and therefore it be considered a Zytiga failure), moving to Xtandi was effective.

[Dastardly]

Hi CharlieBC,

I was very interested to see your reply, and I think I may end up following your footsteps. I will try a reduced dose of Zytiga but, if I can't tolerate that either, I guess I will end up in Xtandi. That's a blow because I was hoping to get maybe 2 years out of Zytiga before moving on, but that's the way it goes.

Good luck to both of us

Dastardly

[Wolfee53]

Anxious to hear if there are different PSA results

[Dastardly in reply to Wolfee53]

So am I Wolfee53. I'll post an update on what's going on after my bloods and clinic meeting.

[Dastardly in reply to Wolfee53]

So, after stopping Zytiga on October 24th, my bloods a couple of days ago show PSA unchanged at <0.1. I had a telephone meeting with my Oncologist and he tells me they will not put me back on Zytiga until I have had my paroxysmal atrial fibrillation checked out by a cardiologist. I am still awaiting an appointment. I have another Oncology appointment in 3 weeks time to see what progress has been made, but I am not expecting any, what with Christmas and NHS nurses striking. Here in the UK, treatment may be free but it sure does take time. I may be about to find out how long it takes for PSA to rise after stopping Zytiga.

Strangely enough, my fatigue levels remain unchanged, although I am sleeping a little better.

Hope all is OK with you.