How much prednisone is needed with abiraterone?

[Tall_Allen]

This is a frequently asked question among men using Zytiga. The answer is highly individual. The benefits and side effects have to be monitored. There is no "one size fits all."

pcnrv.blogspot.com/2019/06/...

[GP24]

Seems Dexamethasone is more effective against the tumor:

Prednisone (5 bid)

PSA declined by ≥ 50% = 63%

Radiographic Progression-free survival = 18.5 months

Dexamethasone (0.5 qd)

PSA declined by ≥ 50% = 88%

Radiographic Progression-free survival = 26.6 months

[Tall_Allen in reply to GP24]

Resist comparisons - small samples - high inter-individual variances.

[GP24 in reply to Tall_Allen]

Yes, but the results of this study show that Dexamethasone is 40% more likely to decrease the PSA value by over 50% and extends the time to radiographic progression by 44% compared with Prednisone.

Therefore I think a large study may show a smaller difference but currently it is more likely that Dexamethasone is more effective against the tumor than Prednisone.

[Fairwind in reply to GP24]

Dex is a far more potent steroid than Pred.. Not as easily managed..

[Tall_Allen in reply to GP24]

I think that there is better evidence for the superiority of dexamethasone than this trial:

europeanurology.com/article...

Unfortunately, the tissue-related side effects seem to be worse with dexamethasone. It is certainly a good idea to switch from prednisone as abiraterone resistance accumulates:

onlinelibrary.wiley.com/doi...

[Fairwind]

When the need for prednisone stops, you have to slowly tapper off taking it, not just go cold turkey. This is especially true if you have been taking it for a long time..

[Hidden in reply to Fairwind]

The dosage with Zytiga is small so it only takes a couple days to taper to zero.

[timotur]

Interesting that taking 2.5mg bid vs 5mg qd of Prednisone lowers mineralocorticoid excess by a whopping 23%.

Not sure what to make of the PSA results showing a 5mg qd having a greater number of PSA decline < 50%. Why would Prednisone (or Dexameth) even affect PSA? I don’t think we can read into that because these are three different population groups.

[Tall_Allen]

"Why would Prednisone (or Dexameth) even affect PSA?" It has an independent action on the cancer, but I think that rPFS is more relevant:

ncbi.nlm.nih.gov/pmc/articl...

Not sure what to make of the PSA results showing a 5mg qd having a greater number of PSA decline < 50%.

The difference is not statistically significant.

"these are three different population groups". It was a randomized study of 4 groups from the same population, but the small sample size makes comparison between groups precarious.

[cesanon]

So what is the general consensus here. It seems Prednisone is going to be the default choice of most docs, unless you advocate for Dexamethasone.

So under what circumstances should you advocate for Dexamethasone? And when should you not?

And when you do advocate to your doc for Dexamethasone, what is your argument. What is the one study you hand them?

[Tall_Allen in reply to cesanon]

Why not switch to abiraterone + dexamethasone when abiraterone + prednisone peters out? You get all of the benefits and fewer of the side effects.

[cesanon in reply to Tall_Allen]

1. I thought the case against dexamethasone is that it has more side effects?

2. If you are asking a doc to do something they don't normally do, you need more than logic. Tall Allen, can you recommend a study to hand them as you're making that argument?

[Tall_Allen in reply to cesanon]

That's why I said, just switch when prednisone stops working. I gave links above.

[Wings-of-Eagles in reply to Tall_Allen]

Great advice Allen as always thanks much from Dan wings of eagles I've been taking zytiga and prednisone for 5 years now and I don't feel any side effects from either maybe a bit fatigue from the zytiga but five years now undetectable speaks for itself

[flyguy]

So I have citrate sensitive PC. Surgery and radiation 7 years ago. On Zynga for 24 months. At 6 months MO stopped Prednisone because of side effects. Constant monitoring of blood levels show no adrenal distress except a slightly low Potassium level addressed with RX supplement. PSA has remained around 0.13 +/-. Any input about this regimen would be appreciated.