If you take warfarin (or brand of warfarin such as Coumadin®), you may be pleasantly surprised by information that gives you new freedoms of choice. The manufacturers of warfarin have removed the recommendation to avoid cranberry juice or cranberry products while you are taking warfarin.
The current product labeling removed the caution statement against cranberry product use as a result of several clinical trials that studied patients before and after consuming cranberry juice1 The two studies agreed with each other and resulted in labeling changes allowing patients to consume normal (8-16 ounces)of cranberry juice.2,3
A 2009 study, sponsored in part by the Department of Health & Human Services, evaluated 8 ounces of cranberry juice in 30 test subjects. The results found no significant interaction between 8 ounces cranberry juice consumed daily for two weeks.2
The second study a year later doubled the volume of cranberry juice to two 8 ounce servings per day in 10 study subjects for a week and also found no interaction between warfarin and cranberry juice.3
Neither study evaluated any cranberry products other than cranberry juice; however, new labeling has removed caution against cranberry juice and cranberry products3.
If you are interested in starting or stopping any food or beverage, it is best to discuss this with your doctor or nurse. Individual patient responses to foods and levels of vitamins and minerals may vary and in some cases, more frequent INR tests are recommended.3
- 1. Bristol-Myers Squibb Company. Medication Guide for Coumadin Tablets and Coumadin for Injection [Package Insert]. Princeton, NJ: Bristol-Myers Squibb Company. 2011
- 2. Ansell, Jack. (2009). The absence of an interaction between warfarin and cranberry juice: a randomized, double-blind trial. Journal of Clinical Pharmacology, 49:824-830.
- 3. Mellen, Chadwick K. (2010). Effect of high-dose cranberry juice on the pharmacodynamics of warfarin in patients. British Journal of Clinical Pharmacology, DOI:10.1111/j.1365-2125.2010.03674.