Stage 4 w/met. On Lupron since 10/19 and a 6 month stint cut short on Zytiga with very minor side effects. Now on Xtandi for 3 weeks and much more brain fog, lack of concentration, hot flashes, fatigue and emotional ups and downs. I noticed similar side effects previously but now seem much more pronounced. The pharm/oncologist suggested reducing the dosage from 4 pills to 3.
Would the reduced dosage effect Xtandi's efficiency
Has any body been in a similar situation or have thoughts on dosage or symtoms?
Would any of the over the counter or prescrip. medications like Prevagen help?
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Zzzgott
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Excessive liver enzyme counts on Zytiga. Was already at <.02 PSA with Lupron/Zytiga but wanted to keep the numbers down with the substantial mets and fully engulfed prostate. Only 3 weeks on Xtandi and the side effects are very noticeable
There is a new second-line anti-androgen called Nubeqa (Darolutamide). I've heard of doctors willing to prescribe that "off label" for patients with extreme side effects from Xtandi. It's currently approved for patients with non-metastatic castrate resistant prostate cancer although it also works if you have metastases. It doesn't cross the blood-brain barrier like Xtandi does and has less of the side effects related to that.
Several of those side effects sound pretty typical.
I seem to recall that the normal dose of 4 capsules per day typically leads to the build-up of serum Xtandi in patients to a steady state of roughly 8 times the level of a single daily dose, within about a month of beginning the treatment. Reducing the dose from 4 to 3 capsules would still probably result in a similar steady state that could still be several similar multiples of a single daily dose. Details of the Pharmacokinetics experienced in the studies leading to Xtandi Approval are in Section 12.3 at this link.
If your doctor approves the partial dose reduction, you can try it and decide for yourself if your subjective symptoms change much within 3-6 weeks after making the change.
Those side effects are typical. I’ve been on Xtandi for 5+ years now. The SE’s seem to be cumulative as well. I’ve been able to reduce the dose by half which helped With SE’s somewhat and it is still effective. My MO, Dr. Sartor said there is still activity (it still works), at 3 or even 2 pills per day vs. the SOC dose of 4. My PSA remains at undetectable levels as long as I continue to take 2 pills, when I tried a doctor directed holiday PSA started to rise so back on it I went.
I’ve read articles and watched Onclive videos discussing Xtandi dosage and the takeaway was that 4 pills - 160mg was simply the SOC dose that was still tolerable, however some men can use a lesser dose and have it still be effective. Of course any change in dose needs to be carefully coordinated with your MO.
My dad has the same issue Xtandi is doing its job of keeping his PSA down but he has some horrible side effects from it confusion, forgetfulness, sadness and extreme muscle weakness in his legs he fell a few times and fatigue he has started to sleep all day so I told him to stop to see if the xtandi was causing these symptoms and they were it’s like I have my old dad back he doesn’t want to go back on the pills but he doesn’t want chemo either? Don’t know what he will do. None of the treatments have made him feel better just worse with all the side effects so confused as to what to do?
Would you be kind enough to tell us more yourself? Age? Location? treatments to date? scores psa/gleason? Treatment centers/location? Doctor's name(s)? All info is voluntary but it helps us help you and helps us too. Thank you!!!
Yikes! I tried to add info treatment info under my account but it was difficult.
67 years old diag 10/19 stage 4 PSA 12 with numerous mets to spline,ribs pelvis, Gleason of 4+3 =7 but all the cores were +. Kaiser checked and I have Chek2 gene. Lupron with Zytiga got the PSA down to <.2. Zytiga for 5 months but AST/ALT 10 times max. After waiting 5 weeks for enzymes to go down went back on Zytiga for 5 days and was 3x max. Dr. Won Kim from Oakland switched me to Xtandi. Scheduled for blood work monthly. 6 months scans looked good with remission and prostate had shrunk .PSA <.2
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Xgeva dosage regimen?
Xtandi failed 
Curious about Prednisone dosage.
