Interesting info about Xeloda

[hutchibk]

Some here may already know this, but I just learned it recently and thought I should share...

A shortage of a critical enzyme for the metabolism of Xeloda (capcetibine) called dihydropyrimidine dehydrogenase can cause someone who is taking it to experience the most severe side effects from it.

I have read that a patient should actually not be taking Xeloda if they lack this enzyme, and it is actually in the paperwork that comes with Xeloda...

Just wanted to share as this is something to keep in mind if you have had severe side effects while on it, and/or something to bring up to your doctor if it is being considered as a treatment for you.

I have had only very mild (if any) side effects, so I can assume that I have plenty of the necessary enzyme, thank goodness!

[Becca]

Brenda, that is interesting since I have lots of side effects. (I envy you having so few side effects!) Is there anyway to make up a shortage of dihydropyrimidine dehydrogenase? Could that be the reason the Tykerb causes lots of problems for some and almost none for others? I will ask my onc about it. My 2nd week on the X is the hardest, and even for several days after I go off it. Thanks for the info.

[hutchibk]

I wish I knew more about it - I asked my doc about it today, and he says that he doesn't necessarily believe that a patient with a shortage of the enzyme should avoid Xeloda, but it is good to know to prepare for more severe side effects. I don't even know how they test for it... and I don't know about making up for the shortage. Let me know what your doc says!

[Diana1993]

I'm just finishing round two of Xeloda. I have the same fatique side effect as other chemo drugs, and runny eye, but otherwise I seem to be tolerating it well. Tykerb is not available in Canada yet, and I decided not to spend $3600. a month on a drug. (I would if I had the available money, but will not borrow) I am hoping our FDA will pass it soon. Did you read the news yesterday that a rash proves the drug is working? I have no rash and I don't want want. Brenda, I'm on my way to San Antonio for a holiday soon. Yahooo!

[koolmom]

My oncologist said if you lacked the enzyme the diarrhea would be so bad you could end up in the hospital. She said you would know within a week of taking the drug. So side effects, even if think severe, may not be related to lack of enzyme.

[tousled1]

I saw my oncologist yesterday and started my Tykerb/Xeloda today. I did ask her about testing me for the enzyme. Her reply was that she has only ever had to test one person. It seems that almost everyone has the enzyme and will have no problems I was told that if I have problems then we will get the test.

[Kim in CA]

This thread is very interesting to me, in that the Xeloda almost did me in back in 2003. A little over a week into my therapy, while walking to the bathroom, I just blacked out. I fell and hit my head pretty hard. Ouch!

Anyway we called my Doc and he said to immediately quit taking the X. Within a few days of stopping the X, I developed a fever and pretty bad diarrhea. Being the brilliant one that I am, I just figured I was coming down with something and didn't call the doc right away. By the time I realized I was really sick and got to the hospital, it took everything they had just to save me. I had transfusions of blood and plasma and was on 4 different "big gun" antibiotics to try and get the infection under control. I was there for about 8 days and lost 15 pounds.

My doctor said that I most likely, bacteria from my intestines got into my bloodstream because of how ravaged my GI tract was, and that's why I was so sick, not to mention the Xeloda had totally wiped out my blood counts. It was like having the high dose chemo all over again, without the stem cell transplant.

The doctor later said that for some reason I wasn't able to metabolize the Xeloda and it just kept building up in my system to very toxic levels. He also said that he would never give me Xeloda again. I asked him if we might just use a much lower dose if I were to ever need chemo options again and he said he just didn't feel good about it. He never mentioned anything about me lacking an enzyme, so I doubt he knew about it.

So although my experience with Xeloda was not good, I often wonder if it is part of the reason I have been NED( in my body) for a good while . I'm always trying to find the good in things, and so I figured since the Xeloda almost killed me, maybe it scared those cancer cells away too!

Hopefully they will learn more about this enzyme and maybe figure a way around not having it for those women and men who may need Xeloda.

Just my musings on a very interesting subject!

Kim