I wonder if anyone has experimented with Zytiga's effects on testosterone?
In particular, there is a lot of research indicating that if Zytiga is taken with food it's absorption by the body is increased. (e.g. pubmed.ncbi.nlm.nih.gov/321...
So, the experiment I'm thinking of is:
1) 1000mg of Zytiga a day w/o food (typical SOC dose and timing).
vs.
2) 250mg of Zytiga a day w/ food (should enhance absorption).
Measure T during both.
(I like to see evidence rather than rely on bro-science or speculation)
If 1/4 dose of Zytiga with food is just as effective as full-dose w/o food, then, of course, it's cheaper for us and might be fewer sides.
You are very special, because people taking zytiga are also on an ADT drug. So the question would be addressed only to people on Zytiga ALONE, am I right?
You did not do any orchietomy, right?
The fact that your SPT works all time would mean that zytiga does not really affect T?Since people on BAT has T falling very fast after SPT injection.
I started on Zytiga about 4 weeks ago, Radium 223 wasn't working and my PSA jumped right up to 600 and was in a lot of pain, PET scan showed progression to femurs, hip and spine (I was on crutches). The first week taking Zytiga I felt pretty rough but last two weeks I've felt great, almost no pain with just little fatigue, Oncologist said he wont know for 6-8 weeks if it's working but the way I feel, I have to think that it is working.
I'm not on ADT as I had orchietomy last Nov.
Since day one I've suffered with pain and I almost forgot what it's like not to be in pain, I don't know how long it will last but I'm making the most of it. The cost of the drug is covered by Gov insurance but taking less would only impact side effects, as I'm feeling pretty good, I'm not sure if I would be willing to experiment with dose.
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Very special. Lol! My mom used to say "Russ is a very 'special' kid"... Hmmm...
You're correct. Probably addressed at people who take Zytiga alone. If they are on ADT then their T is probably pegged low so AA w/ or w/o food won't make a difference. And if they are on SPT then their T is probably pegged high and measurements depend more on when they are done after an injection and less on AA w/ or w/o food.
I never had an orchiectomy.
Coincidentally I blogged this morning about the fact that I'm on AA (zytiga) and SPT yet the combo leaves me with high T and all the things I would expect from active high T.
Taking AA, even though nobody I've talked to knows if it is even needed with SPT, might turn out to be beneficial for me. Because if I ever need to go low T then AA might help get me there fast.
I'm not sure why you are on zytiga while on SPT (seems contradictory for me).
Are you on Dutasteride or Finasteride as stated in your blog?
Could the BP comes from Zytiga or any other drug instead of SPT?
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Who knows why I'm on AA with SPT. I started AA when I was on estrogen-ADT. I continued when I started SPT (my oncs didn't know right away that I was doing SPT). Now my oncs say to not change anything.
BP inc could be from AA or SPT or something else. Seems like it's okay now.
I'm doing Duta and Fina to decrease DHT. DHT is very low compared to what it would theoretically be (T is approx 2500 so DHT should be 125-250. Instead it is 32).
I do the CEA test because it is a general cancer cell indicator. Not as good as PSA for PCa but, according to my SOC onc, not bad as long as I take the results with a grain of salt. So, why not track it? If I survive PCa only to die of colon cancer then beating PCa is rather moot.
Just to clarify, you are on Zytiga monotherapy and self administer T to generate Supra hi levels of T , true? You also take both dutasteride and finesteride to lower DHT, resulting in T = 2500 and DHT of 32 and your PSA response history is ?
I was around 115/65 going into SPT. I slowly crept up to 145/90. I talked to my SOC onc. She thought it might be SPT, might be zytiga, might be something else. I add calcium/magn/pot/phos (fairly low doses of each) and increased my cardio. BP is now about 125/75.
SOC onc doesn't say that SPT has kept PCa under control. She doesn't know what to attribute my success to.
my Supra T is kind of an accidental result for me, a SE of my taking Xtandi without any ADT. So, my T rose immediately to 1600 and then has bounced between 1200 and 1600, even on my current very low dose of Xtandi.
They dont really understand the Supra T"biology" , especially in terms of Pca, as my onc says you are in a different "regime" from those on ADT; its not really clear whats going on.
Dr Danmead has move his focus to BAT and I believe there are some issues with continuous Supra T, not sure anyone is fully exploring this approach unfortunately.
My recollection is that some people do take 250mg Zytiga with food to reduce the cost of the medication. The problem with this approach it's difficult to get consistent absorption, so the actual dose that gets into general circulation can vary widely from day to day. 1000mg on an empty stomach was chosen because it results in much more consistent blood levels.
I also recall that they're working on a form of Zytiga that contains just the right amount of fat in the pill to optimize absorption. Of course that would still need to be taken on an empty stomach.
Side effects should be the same regardless, as they are primarily caused by the level of Zytiga that gets into your blood, and not the dosage that goes into your mouth.
Cheaper and I said that it "might" have fewer side effects. Based on my experience when I take things on an empty stomach, many if not most of them make me a little sick. When I take the same substance with food I usually don't notice it.
I don't see why or how it would have different effects on testosterone. Did you read that somewhere or do you speculate that it could change T effects?
What I'm saying is 1000 mg of abiraterone without food and 250 mg of abiraterone with a high fat meal, if they put the same amount of abiraterone in your bloodcannot have different effects on testosterone. Abiraterone is not bioactive until it gets into your blood. All side effects that depend on abiraterone activity have to be the same if the same amount of abiraterone gets into your blood.
It is possible that you might get less nauseated with the lower dose because there is less unabsorbed drug in your gut.
For me it's a big if to assume that T will be identical. Yes, theoretically IF absorption is increased. Note that reality and theory don't always play as nicely as we'd like.
Also, my question gets to how much fat in the meal? Carbs? Protein?
So I was wondering if anyone had actually tested this out. The theory is ridiculously simple.
I agree that in some men absorption may not be increased to the point that you would get the same amount as 1000 mg w/o food. There is tremendous inter-individual variation, and there are no guidelines for the amount of fat in the meal (it is the fat that increases absorption). With cheaper generics now available there is little benefit to taking that risk. You would have to get an expensive blood test for serum abiraterone, which would negate any cost savings.
The generics were not much cheaper to us under our Medicare Part D plan and Medicare’s doughnut hole favors the brand name. However, by going outside our plan using GoodRx, my husband was able to save quite a bit on the generic.
He and his MO are considering the low dose with breakfast.
Thanks again for all the help you give on this site. In turn,I am trying to help others as my husband starts this journey and we learn.
I considered it before starting and the papers I read from the trials or experiments in Chicago said more SEs so I stuck with SOC. Now I am on 750mg w/on food due to bloodwork. Insurance is paying for this year as I met my max out of pocket quickly with radiation. I may reconsider next year as the cost toxicity would be reduced.
Correct that's what I read when I researched it, more SEs for low dose with food. My MO was OK if I wanted to go this route but decided not to after reading that. I don't think it was a large difference.
I have low lymphocyte count, it dropped to 221 during radiation so they stopped Zytiga until they came back up and restarted me on 750 instead of 1000mg. and I have remained on 750mg.
It would be hard to regulate the foods that have an effect on Zytiga absorption. IIRC, it is fats in foods that are the problem and I suspect not all fats have the same effects.
Hey, RSH1. It is indeed disappointing. I am a firm believer in less is usually more, exact is best. It is very well established that the uptake rate of Zytiga is increased by eating food - which supports the potential for alternative dosing regimens with less Zytiga with greater specificity based on an individual - not some normalized dosing curve. However, since the drug's release rate under these conditions is not substantiated by actual studies, there are no formally recognized alternative dosing regimens that include taking Zytiga with food.
I admit that a study would be problematic. The rigor necessary to track all of the variables associated with the wide array of substances humans call "food" and how each body's individual capacity for making the things eaten bioavailable for that body - especially for a specific drug - is daunting.
The bigger problem is, of course, that Janssen has no reason to stop the money train. Since starting this horrible journey, I have come to understand that the manufacturing of our medications is not a simple process, and once a production process for a specific medication has been decided upon by a pharma company, it is that process forever until a competitor comes up with a new one. Of course, seriously, how many competitors are there for cancer drugs? Zilch - because generics are only copy-cats.
There are other companies out there that are studying ways to improve the bioavailability of fat-soluble drugs, including Zytiga, by improving manufacturing processes. (See mdpi.com/search?q=KinetiSol... ) . But how do we force efficiency into what is effectively a monopoly market for a specialty drug?
After all of this prattle, my suggestion is to talk simply talk to your doctor about taking with Zytiga with food if you are interested. I did! - Joe M.
I talked to my SOC onc a couple of months ago about taking Zytiga with food. Off the record she was okay with my taking 1/4 dose with food if it came to that or no Zytiga at all (at the time I was having issues with the manufacturer copay but since cleared it up so it's only $10 a month for me).
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