Adjusting dosage of Abiraterone with low fat meal

[Ronnie7C]

Prostate cancer diagnosed in March 2020 (Stage 4 Gleason 9). Have recently completed 6 cycles of chemo, with ADT injections every 3 months. My PSA, which was originally 76, dropped to 1.6 in December 2020.

I don't have medical insurance so have been undergoing treatment at the public hospital.

Apr ’21 started Abiraterone (Zytiga) 500mg taken with low fat breakfast of approx. 300 cals and also taking Prednisone.

May ’21 PSA further drops from 5.6 - 0.5. Then in June ’21 again drops to 0.2

Jul ’21 lower my dosage of Abiraterone to 250mg taken with low fat breakfast of approx. 300 cals and also continue with Prednisone.

PSA remain unchanged at 0.2 from Jul – Oct ‘21

In Nov ’21 had to go on overseas trip so unable to continue with regular local hospital blood tests and consultations. The trip was originally planned to be for 2 months but due to Covid and airline flight problems ended up taking close to 5 months. Unfortunately, during that period I missed a regular 3 monthly ADT injection (unable to see a doctor or get to any hospital) . Throughout the overseas trip, I continued my medication routine of Abiraterone 250mg taken with low fat breakfast

Once back from the overseas trip and resuming treatment at the local public hospital, my PSA readings have been rising as follows

Apr ’22 2.01

Jun ’22 2.90

Jul ’22 4.40

Aug ’22 6.60

In September, I have bone can and CT scan scheduled to help identify what changes have occurred since last scans.

In hindsight, I wonder if I lowered my dosage of Abiraterone (500mg down to 250mg) too soon or if I should just have continued on the 500mg dosage.

I had found it very difficult to handle the medication dosage of 1000mg of Abiraterone on an empty stomach.

Any advice or comments on my situation would be much appreciated.

[Jost-58]

Take it together with your breakfast not on an empty stomach. Many has changed to that procedure.

[Alturia in reply to Jost-58]

The OP explained that he didn't like taking it on an empty stomach and so started taking it with a low fat breakfast. His question was whether he should have stayed at the 500mg dose instead of lowering it to 250mg.

[Jost-58 in reply to Alturia]

He can higher with food. Need that to stop PSA increase. Maybe switch cortisone

[Ronnie7C in reply to Jost-58]

Thanks for the advice. I currently take it with my breakfast but was interested to know if taking FULL dosage on empty stomach would help my PSA to drop.

[Tall_Allen]

If you cannot afford full dose abiraterone, take a reduced dose with a high fat breakfast.

[Lslal in reply to Tall_Allen]

Why with a high fat breakfast!

Isn’t it supposed to be taken on an empty stomach?

[Tall_Allen in reply to Lslal]

Full dose on an empty stomach.

[Concerned-wife in reply to Tall_Allen]

the study was based on low-fat. “The other half were told to take one-fourth of the standard dose, a single 250-milligram pill, with a low-fat breakfast such as cereal with skim milk. Patients were advised to avoid high-fat items such as bacon or sausage”

[Ronnie7C in reply to Concerned-wife]

Thanks for your comment. Yes, I was following the single 250mg option but with the PSA continuing to gradually rise, I'm now contemplating trying the Full 1000mg on empty stomach to see if it makes any difference to PSA. Figure it might be worth a try.

[Concerned-wife in reply to Ronnie7C]

it is supposed to have same efficacy. However, on an empty stomach the full dose might be more predictable..rather than worrying about breakfast effects.

[Ronnie7C in reply to Concerned-wife]

On that point, I totally agree with you. Thanks again for your comments

[Tall_Allen in reply to Concerned-wife]

It seems that the more fat in the meal, the more absorption. But now with lower cost generics, there is no reason to take anything but the 1000 mg dose without food.

"In mCRPC patients, abiraterone [plasma concentration] AUC was ∼2-fold higher with a high-fat meal and similar with a low-fat meal versus modified fasting state ... Adverse events (all grade ≤ 3) were similar, with high-fat/low-fat meals or fasted/modified fasting state. Short-term dosing with food did not alter abiraterone acetate safety."

accp1.onlinelibrary.wiley.c...

[jfoesq in reply to Tall_Allen]

Tall-Allen Are you saying this study indicates I can eat a high fat breakfast when taking my 1000mg Zytiga? More importantly, can I drink my coffee along a little milk and one teaspoon of sugar?

[Tall_Allen in reply to jfoesq]

No it is not saying that you "can eat a high fat breakfast when taking my 1000mg Zytiga." It is also not giving you permission to take a full dose with any food.

[jfoesq in reply to Tall_Allen]

Thank you for clarifying that for me.

[MateoBeach]

we’re those rising PSA tests done while you were back on ADT? If so, then you have apparently arrived at castrate resistance.

Abiraterone +p is capable of giving castrate testosterone levels without added ADT (Lupron etc.) if you just could have had a testosterone blood test you could have known if the 500 mg or 250 mg Abi was sufficient (T <20) or not.

You could try a switch from prednisone to dexamethasone to see if that helps for awhile. But it may be time to move on to a different treatment. I would get a PSMA PET scan to see if a candidate for Pluvicto.

Also try to get Provenge now that you are CRPC. Paul

[Ronnie7C in reply to MateoBeach]

Many thanks for your input. Will definitely discuss these issues with my Oncologist at our next meeting.