Zytega and fasting : We have all heard... - Advanced Prostate...

Advanced Prostate Cancer

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Zytega and fasting

Schwah profile image

We have all heard that Zytega should be taken by fasting two hours before and one hour after. I try but it l’m not perfect like many of us I suspect. Especially since the prednisone is supposed to be taken on a full stomach. Does anyone know if the reasoning is to avoid upset stomach or other irritation or if the actual efficacy of these pills is impacted by not fully following these requirements? In other words does the stuff not work as well if you screw up a little and/or is there any actual danger to screwing up. I assume it’s always better to not miss a dose than to meet these eating require 100%.


20 Replies

The problem is it works too well when taken with food. With a low-fat meal, you should reduce the dose to 500 mg; with a high-fat meal, you should reduce the dose to 250mg. The prednisone should be taken around 8AM and 6PM because cortisol normally peaks at those times.

Schwah profile image
Schwah in reply to Tall_Allen

This is what drives me nuts. The dr and all the pharmisists at the specialty pharmacy instruct you in no uncertain terms to take it without food 🙈🙈🙈. Now it looks like you should take it with food. Why is working “ too well” as you say, a bad thing. Seems like it should be a good thing if it’s purpose is to stop the Cancer ? Is it because of potential toxicity ?

Thx BBtuce and Tall Allen for the info. I love this fricken site. More knowledge here than with most oncologists have.

Steve s

Tall_Allen profile image
Tall_Allen in reply to Schwah

When they originally did the dose-finding study on Zytiga, they used the 1000 mg/day fasting dose. So that's the dose they have the most info on. Above that optimum dose, you're getting more toxicity and not much treatment, so you should not exceed that. More is not better. Because absorption varies with food intake, and the amount absorbed will vary from man to man, they left 1000 mg/day fasting as the standard dose.

But the stuff is expensive, and many men would like to take smaller doses if they can get the same benefit. There have been 3 small studies of low dose Zytiga with food:

With a low fat meal (n=36):


With a high-fat meal (n=21):


Comparing low fat (n=6) and high-fat (n=18):


All of the studies were very small, so you should only reduce the dose under advisement and close observation by your oncologist.

Spitzz profile image
Spitzz in reply to Tall_Allen

I take my Zytiga when I wake at about 7 or 8 and either go back to bed or start my day. If I start my day I have some coffee or tea and by the time I'm ready to leave the house or start a project the hour is gone the day is normal. I take my Prednisone when ever I eat....

This is what works for me......

DeanNelson profile image
DeanNelson in reply to Spitzz

That's my routine also!!!

Thanks for that information. It widens my understanding of administration of the medicine. I just started last week. Taking 1000 once a day with Prednisone. Was advised to take on empty stomach. We eat dinner late, so I have an afternoon snack around four and take the Zytiga at 6. Eat at 7 or 7:30. Your explanation gives me more to discuss with my MO.

I have been through this with Harvard Medical, Best way is to do it as recomended with fasting first, If it fails , it may not be being absorbed this is when adding food may come in under supervision of medical Oncologist, as adding food can raise liver numbers in some men. Also if it stops working sometimes switching prednisone for .5mg dex may work. I wish you the best. I found the easiest way to take it while fasting is to take the zytiga when you get up to pee at 5 am then go back to bed for an hour. It is better to not miss a dose.

Just do what your Medical Oncologist tells you to do.

Dan (dx stage 4, widespread metastatic disease to bone and lymph in distant sites, Gleason 10 bpsa 148, at 49 yrs, in June 2006, currently 62.)

I wish you the best

DeanNelson profile image
DeanNelson in reply to Dan59

Dan59, you were diagnosed in June of 2006?

Dan59 profile image
Dan59 in reply to DeanNelson

Dean, Yes 2006 , in my 13th year

DeanNelson profile image
DeanNelson in reply to Dan59

Omg..., I was Dx on 5/8/2018 with Gleason 9, same kind of Mets. That's gives me a lot of hope... But mine is ductal, which I haven't met a lot of men with...My highest PSA ever was 3.66.

my husband struggled with the drug, too. he set his alarm for 3 a.m., ate a yogurt, took the drug and went back bed. when he did this, he had no problems.

I take my Zytiga at around

6:00 AM With a whole bottle of Spring water, take a walk around 7:00, Prednisone at 8:00 or so with Breakfast. I'm a creature of habit so the routine has gotten to be my everyday habit now. The water was suggested to me on this site and it really does help. Leo

This is exactly the way I take the Zytiga and prednisone, fairly simple way to manage both.

M-F I set an alarm for 5:30am to take my 1000mg Zytiga. I go back to sleep until 6:00am when I get up and get ready for work. I take my first Prednisone between 6:30am-7:00am with my breakfast. I then take my 2nd Prednisone at 1:30pm. On the weekends I take my Zytiga whenever I wake up, generally by 8:00am and Prednisone an hour later followed by the afternoon dose of Prednisone sometime between 1:30-3:30pm. My MO knows of my routine and has not suggested any alternatives at this point. It works for me doing this routine!

Sounds fine, but I have been unable to find a definition, as in gms of fat/meal, for a low or a high fat breakfast. A check of the abstracts provided (thanks) does not help. Anyone?

Tall_Allen profile image
Tall_Allen in reply to herb1

That's why you should not attempt this without medical supervision. Most people would agree that a high fat breakfast would include bacon and eggs (ie mcD's sausage, eggs & cheese McGriddle has 32 g of fat), and a low fat breakfast would be something like cereal with 2% milk and coffee (approx 5 g fat). Similarly for dinner, a high fat meal would be a typical MaDonald's - 1/4 lb cheeseburger and fries (43 g of fat), whereas a low-fat dinner would be skinned chicken breasts, rice and broccoli (5 g of fat). Of course, if you consistently eat food of the high fat sort you'll certainly die more quickly of something other than prostate cancer.

herb1 profile image
herb1 in reply to Tall_Allen

Tall_Allen: thanks, at least that tells me what "most people agree". But I still wonder what the docs doing these studies considered hi and low! And, does anyone fighting PCa still live as if he's twenty and invincible?


The discovery that Zytiga dosing could be reduced by taking with a light low fat meal was determined empirically by outside-the-box physicians working with patients, probably to help them afford this obscenely expensive medication. Obviously, it is not in the financial interest of the manufacturer to support additional research to develop guidelines to assist doctors in titrating dosing in this way.

I presume most physicians will not step outside the mfg recommendation for liability concerns, so don’t expect you doc to support you if you want to try reduced dosing with food. If he/she is supportive of this approach, with close monitoring, consider that doc a ‘keeper’.

I’ve been on this for 6.5 years. I take a Lanzaprozole and Prednisone after breakfast at 9 am, then 4 tablets of Zytiga (Abiraterone in the U.K.) at 11 am. The timing works well for lunch any time after 12 pm. I’ve never missed a tablet throughout this period.

My instructions were to take 1 hour before eating or 2 hours after. As Tall_ellen says with food you get too rapid absorption which doesn't really provide a benefit and increases side effects. I get up and take it and omeprazole, usually with glass of orange juice and something small, like half or a third of a banana to make sure it goes down. I the shower and prep my day, then have breakfast and leave for work. You take the prednisone with food to lessen stomach upset. That's also the reason for the omeprazole.

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