Q. I have atrial fibrillation, an abnormal heart rhythm for which I take Tambocor (a heart rhythm drug) and warfarin (a blood thinner). I also have arthritis. I was taking Tylenol for it, but my lab tests went haywire. I think the Tylenol was affecting the warfarin, because after I stopped taking it my bleeding time results came back into balance.
I know warfarin is crucial to prevent a stroke, but I find it very challenging to figure out all the conflicting information about it. I had been told that Tylenol would be fine, but it isn’t. I’ve also heard different advice about cranberry juice and vegetables. Can you send me any information on warfarin and diet?
A. Warfarin, also prescribed by the brand names Coumadin or Jantoven, is a life-saving drug but it can be tricky to use. It interacts with many other medicines and even many foods. While acetaminophen (Tylenol) could be used for occasional pain relief, regular use can raise the INR (a measure of blood coagulation) and increase the risk of dangerous bleeding.
Cranberries may also increase the risk of bleeding, while vegetables rich in vitamin K such as brussels sprouts or kale can counteract warfarin’s action and increase the risk of a blood clot.
We are sending you our Guides to Food, Drug and Coumadin Interactions for more details on this important medication.