Abiraterone dosage

[Quarky]

This is somewhat related to my question concerning my elevated alt/ast levels that I asked about last week. Some of you mentioned that while on Abiraterone, you experienced a significant increase in those levels.

My question here has to do with the proper dosage of Abiraterone. I'm currently taking 1000mg/day, on an empty stomach, and waiting for an hour before eating. This is what my mo has prescribed, and I understand that this is the standard dose for pca. I'm curious about how this particular dosage level was derived? I assume that there are studies or clinical trials that show this to be the optimal dosage, and maybe Tall_Allen knows what that research is.

My mo has suggested that I consider reducing my dosage to 3 pills/day, to 750mg if I have concerns about possible liver injury on Abiraterone, but I wonder if that reduction might compromise the cancer fighting (or testosterone reducing) effect of the medication.

I've also read that some people take only 250mg dose of Abiraterone with food. Is that as effective at taking 1000mg on an empty stomach? How is one to know how much of it is being absorbed at a beneficial dosage level?

Thanks in advance for your responses. This group is an invaluable source of information and I'm very grateful for all of you.

[Magnus1964]

I was on a drug trial with Abiratorone. The dosage was 1000mg. However, in the beginning I was told to take it on an empty stomach. My PSA fell. Then I was told to take it with food, my PSA fell more.

As to dosage, I always thought 1000 mg was too much. You might start with 500 mg, and if needed go to 1000 mg.

[Quarky in reply to Magnus1964]

Thanks Magnus!

[Tall_Allen]

There was a Phase 1 trial of Zytiga that arrived at the optimal dosage. They tried several doses.

250 mg with food gives the same average absorption of abiraterone as 1000 mg without food. Only the amount absorbed affects toxicity, so the toxicity is exactly the same on average. However, even though the average absorption is the same, there is more uncertainty in the amount absorbed with food. Without food gives better control.

Some patients allow the liver to get used to the proper dose by cutting back temporarily and slowly increasing the dose to the proper level.

[Quarky in reply to Tall_Allen]

”However, even though the average absorption is the same, there is more uncertainty in the amount absorbed with food. Without food gives better control.”

Thank you TA. That’s what I thought might be the case and seems logical to me given uncontrolled variables like the amount of food consumed, fat content of food, body size, etc.

[Usernameitis in reply to Tall_Allen]

My husband is on 250 mg with the 5 mg of prednisone. His Doc is Director of Research at CU Health and told us same thing - studies show that WITH FOOD, people derive same benefit as 1000 mg WITHOUT food.

[treedown]

My first 2 years of Abiraterone was at 750mg due to issues with my WBCs. I am back on it at ful strength now after recurrence. The eating 1 hour after taking is when I take my Prednisone with food, which I assume you are taking as well.

[Quarky in reply to treedown]

Yes, exactly what I'm doing as well. Thanks.

[Sagewiz]

I had the same protocol as you do. However, since my fatigue was so debilitating they reduced it to 750mg for 1 quarter and then reduced it to 500 mg for the last quarter since my PSA didn't increase. We will see how that impacts me at the next quarterly check.

[Quarky in reply to Sagewiz]

Thanks Sagewiz. Haven't been too bothered with fatigue recently, but I definitely was when I started on adt. I've realized that exercise definitely helps. Take care and stay strong!

[Chrisbaird]

Started on 1000gms 4 years ago within 3 months had liver toxicity came off Zytiga for a month then went back 500gm an hour before food PSA has been undetectable for last 3 years on this dosage fatigue and hot sweats my main problem as advised keep as active as can walking daily

[85236442968]

Quarky

I started on 1000mg of abiraterone with 5 mg of prednisone. After 3 months, the MO reduced the abiraterone to 750 mg due to extreme blood pressure issues. Have been on the 750 since, total of 10 months. PSA is <.04 (undetectable and testosterone is <7.00 undetectable) Yes I have all the other side effects. However my PET scan in April showed zero uptake on the prostate, zero uptake on the periaortic nodes, and only one pelvic node left with any uptake. It was reduced to 2.5 from 16.3. Of course this was also accompanied by radiation.

Bottom line is the 750 seems to be working fine and I am looking forward to going to 500 at 1 year.

[Quarky in reply to 85236442968]

Thanks. Sounds like you're on the right path!

[GrantB47]

I started at 1000 like everyone else but I developed a very severe cough which eliminated any chance of a decent night's sleep and was actually painful so I stopped on my own and my MO ok'ed it. Then after reading a comment here I decided I'd try 500 with the same regimen, again with the approval of my MO. It has been about 9 months in at this point and T is less than 4 and PSA is less than .016. Just one person's story though.

[Quarky in reply to GrantB47]

Thanks Grant. Haven't heard about coughing as a potential se, but I'm very glad to hear that it was resolved by lowering the dose of abi.

[God_Loves_Me]

Quote from Allen "Rising ALP and declining PSA - Liver stressed ". There should be medicine to manage ATL and APL. Everything depend on PSA when you think to reduce dosage

[Professorgary]

As TA said, taking 250 mg with food will result in the same side effects as 1000 mg without food. You need to cleanse your liver. I take 2800 mg of curcumin extract with black pepper extract daily. For many years I had high bilirubin. 1.8 before starting curcumin. It is now .5 and alt and ast normal with alp in the seventies. I suggest you google curcumin to cleanse the liver and discuss with your doctor. By the way it also lowers blood pressure. God bless.

Results after curcumin.

[Mascouche in reply to Professorgary]

Milk Thistle is also supposed to be good for cleaning up the liver. Is this correct?

[Professorgary in reply to Mascouche]

I have read it is but never tried it. I got onto curcumin by accident. When my orthopedic doctor told me I’d have to take Celebrex for back pain I googled Celebrex and Pca to see if it would have a detrimental effect. To my surprise the search engine brought up Celebrex and curcumin to fight prostate cancer. I then started researching curcumin and found some interesting reading. If you make a list of all the side effects of adt and then google for that se and curcumin think you will be amazed. You can start with fatigue, weight control, glucose levels, bp,lipid levels and on and on. I would caution you to discuss with your mo first and be sure to drink of water. My kidney function was high 80s before curcumin, it is now 117.5. Hope this helps, God bless.

[Mascouche in reply to Professorgary]

It was fate (and goodle) that put curcumin in your path :).

For my part I have been taking two pills of turmeric every dinner for the past 3 years at least and I have powder curcuma that I sprinkle over my eggs and salads.

But I still take Milk Thistle and Dandelion every 2-3 days to help the liver detox from ADT drugs. If you look at this link healthline.com/nutrition/da... you will find that it offers several of the benefits that curcumin offers.

[Quarky in reply to Professorgary]

Thanks! I add curry powder to a lot of my food, but I know that curcumin only makes up a very small percentage of that. I'll talk to my mo about including curcumin into my diet.

[GoBucks]

Here is my cynical view. The clinical trial found that 1000mg dose was the highest/best tolerated dose. No need for further testing. 4 pills a day monthly = 11-12k per month for J&J. Only 2 pills per day = 1/2 the income. My trial of 1 showed that 750 mg reduced testosterone and kept me at <0.01 for 4.5 years. Plus 2 more years off all meds.

[Professorgary in reply to GoBucks]

It’s funny that you bring up money. My new oncologist immediately asked me if it was the money when he saw that I take 250mg with food. Honestly, if the stuff was free, who in their right mind would take 4 if 1 will produce the same result. As I said my new mo and soon to be fired mo.

[Quarky in reply to GoBucks]

My mo and I will be talking about the risk/benefit of reducing my dosage to 750mg. Glad that it was effective for you. Thanks.