??? about grapefruit...

[coffeelover]

Still learning alot about warfarin,INR,etc... just wondering what effect does eating grapefruit have on warfarin/INR? Anyone have any experiences with INR changes after eating grapefruit?

 

[tom in MO]

I eat grapefruit and am on warfarin. I do not eat more than a couple a week and I never eat the same fruit two days in a row. I have seen no effect on my INR, I test biweekly at home.

 

[dick0236]

I have eaten grapefruit ever since my surgery..........without any problem with INR. I wasn't even aware of any kind of posssible interraction with warfarin for, at least, my first 30+ years. It's like many other foods that are OK...you have to use a little common sense. I eat grapefruit and/or drink grapefruit juice a few times each month.

 

[Protimenow]

The big deal with grapefruit, I think, is what happens when you also take a statin drug (Lipitor and others). Grapefruit in any form is strongly contraindicated. And, as in Dick's case, even if grapefruit should cause a spike or drop in INR, if the use of the grapefruit or its juice is consistent, dosing can be modified to accommodate for any effects. And, as others have also noted, drinking a LOT of the stuff over a short period may have caused some changes in INR -- but such use is probably pretty atypical for nearly all of us.

This is where having your own meter and being able to self-test can be useful for confirming whether or not any changes have occurred.

 

[pellicle]

I have eaten grapefruit ever since my surgery..........without any problem with INR. I wasn't even aware of any kind of posssible interraction with warfarin for, at least, my first 30+ years. It's like many other foods that are OK...you have to use a little common sense. I eat grapefruit and/or drink grapefruit juice a few times each month.

Do you eat it regularly or irregularly?

Have you been eating it for a period just prior to testing?

You should contact the academic in question with your information. It is possible that the enzyme in question does not have a uniform behaviour in all members of the population .

Bottom line is that these are indicators of interaction. IF grapefruit is important to you and avoidance is not an option then prudence would be to involve testing of your INR involving it as well as not involving it. Keep in mind warfarin half life in your testing.

 

[pellicle]

I recommend you read this www page as a good starting point

http://www.abc.net.au/radionational...it-medication-interactions-increasing/4404334

There is a mp3 podcast to listen to as well which makes it clear.

If in doubt develop a reasonable testing strategy and see if you see any influence. I assume that a glass now and then (less than
weekly) will have minimal effect

 

[coffeelover]

Tom, Thanks for sharing!

 

[coffeelover]

Pellicle,
Thank you for the link. Will listen to that audio to educate myself on warfarin and interactions.

 

[coffeelover]

Dick0236,
Thanks for sharing you experiences with grapefruit/diet and warfarin.I will chat with MD next week when I see him.
Thanks!

 

[pellicle]

Pellicle,
Thank you for the link. Will listen to that audio to educate myself on warfarin and interactions.

you are welcome ... though the article is not warfarin specific

 

[Protimenow]

It may make sense to print the article and bring it with you. I doubt that many doctors know about any possible interactions between grapefruit and coagulation (and anticoagulants).

 

[pellicle]

btw the principle involved is that grapefruit juice contains a chemical which interferes with an enzyme in your digestion which is intended to block (what the body regards as) toxins from entering your system.

Thus the effect is to alter your body uptake of the drug and increasing the amount that gets inside you . Disturbing dose amounts and regulation

 

[ski girl]

Yeah I had an INR issue that involved grapefruit juice! I had forgotten I was told to avoid it as it slows warfarin metabolism in the liver, increasing your INR. I got blood tests for something unrelated and they decided to do an INR as well - my INR has been amazingly consistent at 3.0 for a year. I was blown over when they came back with an INR of 9.0!

So I did a home test an hour later and it was 8.0, off the the hospital for me and another 8.0.

The cuplrit would have been the grapefruit juice as I'd had a large bottle of it over the previous week and I had made no other changes. So I stay away from it now - but I may just be overly sensitive to GJ.