Dr DIMITRIOS – JAMES MANOS
1 January 2012

Herbal products that may potentially increase the risk of bleeding or potentiate the effects of warfarin therapy include: angelica root, arnica flower, anise, asafoetida, bogbean, borage seed oil, bromelain, capsicum, celery, chamomile, clove, fenugreek, feverfew, garlic, ginger ginkgo, horse chestnut, licorice root, lovage root, meadowsweet, onion, parsley, passionflower herb, poplar, quassia, red clover, rue, sweet clover, turmeric (curcumin), and willow bark (1).

Products that have been associated with documented reports of potential interactions with warfarin include: coenzyme Q10, danshen, devil's claw, dong quai, ginseng, green tea, papain, and vitamin E. Interpretation of the available information on herb-warfarin interactions is difficult because nearly all of it is based on in vitro data, animal studies, or individual case reports. More studies are needed to confirm and assess the clinical significance of these potential interactions. There is evidence that a wide range of alternative therapy products have the potential to interact with warfarin (1).

Cranberry, Dong Quai (Angelica Sinensis), garlic, glucosamine +_ chondroitin, papaya extract, Tan – Shen (Danshen) and vitamin E may increase the effect of warfarin (papaya extracts’ effect is less than the rest mentioned above) (2).

Panax ginseng and St. John’s Wort may decrease the effect of warfarin (ginseng’ effect is less than St. Johns Wort) (2).

Some herbs that may interact with warfarin include: feverfew, garlic, ginger, ginkgo, ginseng, bilberry, dong quai, turmeric (curcumin), meadowsweet and willow, chamomile, motherwort, horse chestnut, fenugreek and red clover. Omega 3 fatty acids (oils) may also interact with warfarin (3). Warfarin may interact with many Chinese herbs (4).

Herbs & dietary supplements that may interact with warfarin include: chondroitin plus glucosamine, coenzyme Q10 (also known as ubiquinone, ubidecarenone), danshen (Salvia miltiorrhiza), devil’s claw (Harpagophytum procumbens), dong quai (also known as danggui), Chinese angelica (Angelica sinensis), feverfew (Tanacetum parthenium), fenugreek together with boldo (Peumus boldus), fish oil supplements that contain eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), Ginkgo biloba, ginseng (Panax ginseng), Chinese ginseng, Japanese ginseng, Korean ginseng, American ginseng (Panax quinquefolius), green tea (Camellia sinensis), horse chestnut (Aesculus hippocastanum), Lycium barbarum (also known as Chinese wolfberry, Di GU Pi, Goji berry, Gou Qi Li), papaya extract (containing papain), certain brands of quilinggao (also known as ‘’essence of tortoise shell’’), St. John's Wort (Hypericum perforatum), vitamin A, vitamin K, and wintergreen (used on the skin, also known as methyl salicylate) (5).

Foods that affect warfarin or blood clotting include: avocado, cranberry juice, flax (flaxseed), garlic, ginger, mango, onions, papaya, seaweed (sushi wrap), and soy protein products (including soymilk and tofu) (5).

REFERENCE (LINKS)

1.http://www.ncbi.nlm.nih.gov/pubmed/10902065

2.http://docs.google.com/viewer?a=v&q=cache:svMqtG50ogoJ:
curriculum.toxicology.wikispaces.net/file/view/Warfarin%
2BGuidelines%2Bwith%2Bcopyright%2Bvs%2B5.0.pdf+Queensland+
government+warfarin+guidelines&hl=el&gl=gr&pid=bl&srcid=
ADGEESiLm9MHuRZdvuRhLyocTzkAh7fLSxrDDoIPriKEveJU_0kaj8zRy_
Uc-vdLU5U8CihMA26I-ZEna4fMSR1AoHcS7oEMGdumH6wRVZEfBz6-6zOZy
DSzmoTFNBWTIJt8F99VxYoi&sig=AHIEtbRlVz1V434j6hg71aZUupp_yB9Hmw

3.http://www.itmonline.org/arts/herbdrug2.htm

4.www.balancedconcepts.net/warfarin_chinese_medicine.pdf

5.http://www.guch.org.uk/experiences/dietandwarfarin