Cora hayes,

Thanks for your great question. 

Warfarin (brand name - Coumadin) is a blood thinner used in the treatment and prevention of blood clots.  Because the indications for the use of this medication have broadened over recent years, more people are taking this medication than ever before.  Rather than tell you what foods are allowed, I concentrate on foods that can influence the effectiveness of the warfarin.

Because certain foods can impair the effectiveness of warfarin, it is important to watch what you eat while taking this medication.  Until recently, doctors would advise their patients to avoid foods high in vitamin K which can counteract the warfarin, but now most physicians are advising the continuation of these foods in the diet, but be consistent in your diet.  In other words, if you routinely eat spinach and broccoli, you may continue them as before, but try to keep the amount and frequency constant.  Wide variations may influence your warfarin.  Foods that are high in Vitamin K include leafy green vegetables such as spinach and broccoli. 

As far as beverages are concerned, try to avoid drinking green tea which is very high in Vitamin K.  Try to limit your amounts of cranberry juice and alcohol as they can actually potentiate the action of warfarin which could result in bleeding.

So, eat a sensible, consistent diet.  IF for some reason you are unable to eat for a couple of days (because of a stomach virus or other reason), be sure to speak with your doctor who might temporarily change your warfarin dose.  Also, be sure to check with your doctor before starting any new medication (prescription or over the counter) as well as any herbal supplements and vitamins.

I hope this has been helpful.

Martin Cane, M.D.