Cranberry juice and INR

[csutherland]

Jerry's INR range is supposed to be 2.5 - 3.5 and for the most part it stays very stable. Maybe 3 times a year he'll have a slight bump either way but they almost never change his dosage. He gets checked monthly.

This past week it was 4.3 so they had him drop the dosage by 5mg that night and then continue on as usual. Unfortunately he had had a skin cancer removed from the top of his ear right before he went to the coumadin clinic. That thing bled profusely for about 24 hrs. (Have you ever tried to bandage the top of an ear?)

He was asked if he'd eaten lots of tomatoes. Not particularly. Suddenly I remembered reading something on here about cranberry juice. He's gotten hooked on cranberry/grape cocktail this summer. He drinks about 1/2 gal a week, but would drink that much in a day if I kept it on hand. I've read some of Al's postings and that doesn't seem enough to cause a problem anyway. Also, we love canned cranberry sauce and eat it frequently with certain meals.

Also we're in one of the places where it has been extremely hot with several 100 degree days in a row 3 different times. Does the heat affect INR?

 

[Ross]

There is no interaction between Cranberry Juice and Warfarin. That has been settled once and for all.

More info: http://www.warfarinfo.com/cranberry.htm

None of us know exactly why, but yes, heat does seem to impact INR. I don't know if it's because we dehydrate or exactly the trigger, but we have all complained about it.

 

[Karlynn]

Heat does impact my INR. I'm in the midst of my Summer Pendulum routine. Last Monday my INR was 2.4 at 63 mg/week. Since I really prefer to have my INR over 3 I bumped it up to 66 for this last week and tested yesterday rather than holding the dose. Well I should have held the dose, because we then had all that 100+ degree weather. Yesterday my INR was 5. So I'm back to 63.

 

[Guest]

I don't think that my website says that there is no interaction. At the end of the article Jo Yacko notes that there may be an interaction at high quantities of cranberry juice. "High quantities" has not been defined.

Heat seems to affect the INR for people who work outside, or who live in non-air-conditioned houses. However, most people spend less than 12 hours per day at the 100 degree temperature so it makes no difference for most people.