PDA

View Full Version : Grapefruit?


whatz
12-14-2009, 07:15 AM
Somewhere down the line I've heard you are supposed to avoid grapefruit while on chemo. Here are my questions:
1) is this true? if so why?
2) if 1 is true...does this apply to Herceptin as well?
Thanks for answering.

TanyaRD
12-15-2009, 01:25 PM
Oncolink.org had a good explaination for the potential interaction between chemo and grapefruit. See below.


Dear OncoLink "Ask The Experts,"
I am wondering if you clear up the mystery surrounding the contraindicated use of grapefruit/and or juice during chemotherapy?



http://her2support.org/images/answer.gif
Katrina Claghorn, MS, RD (http://her2support.org/experts/ask.cfm?c=4&id=12), Registered Dietitian at the Abramson Cancer Center of the University of Pennsylvania, responds:
Grapefruit can block the activity of an enzyme in the intestine that is involved in the metabolism of certain medications. Because the medications can't be broken down, blood levels may rise and become toxic. Drugs that are affected include cholesterol lowering medications, beta-blockers for high blood pressure, some psychiatric medicines, immuno-suppressants, and protease inhibitors. The only chemotherapy drug that grapefruit is definitely known to interact with is Vincristine (http://her2support.org/treatment/article.cfm?c=2&s=10&id=156). However, there are concerns about the interaction of grapefruit with other chemotherapy drugs based on our knowledge of the way they function. If you regularly eat grapefruit or drink grapefruit juice, ask your doctor or pharmacist about possible medication and chemotherapy drug interactions. Other citrus foods and juices, such as orange juice, do not appear to interfere with medication metabolism.

Mayo Clinic has a nice chart displaying potential drug interactions.
http://www.mayoclinic.com/health/food-and-nutrition/AN00413

whatz
12-15-2009, 02:44 PM
Thanks for the info. I guess I'll be OK with the sometimes grapefruit breakfast and Hercepting :-)

caya
12-16-2009, 06:55 PM
Grapefruit also interferes with Tamoxifen.

all the best
caya

Sandra in GA
12-18-2009, 03:37 PM
I had to avoid grapefruit while I was on lapatanib (Tykerb). Since I took my last Nov. 18th, I have been enjoying a half almost every morning! That was one of the warning labels they always put on my bottles down at Mayo.

Unregistered
12-28-2009, 08:30 AM
You may also want to visit the druginteractioncenter.org website.