(references available on request)
Although most herbs that affect coagulation have been associated with anticoagulant, antiplatelet, or fibrinolytic properties, a few herbs have coagulant properties. Specific herbal products that may potentially alter blood parameters are listed in the table below. These herbs are listed for reference; however other herbs may affect the anticoagulant response. Further investigation is needed to evaluate the effects of herbal products on warfarin therapy.
| Herbal products that may affect blood coagulation |
Mechanism
|
Type of coagulation effect
|
| Agrimony | Coagulant, human | Coagulant |
| Alfalfa | Coumarin constituents | Anticoagulant |
| Angelica | Coumarin constituents | Anticoagulant |
| Aniseed | Coumarin constituents | Anticoagulant |
| Arnica | Coumarin constituents | Anticoagulant |
| Asafoetida |
Coumarin constituents and anticoagulant in vivo |
Anticoagulant |
| Bogbean | Hemolytic activity | Anticoagulant |
| Celery, seed or extract | Coumarin constituents | Anticoagulant |
| Cassia | Inhibits platelet aggregation | Anticoagulant |
| Chamomile, German | Coumarin constituents | Anticoagulant |
| Chamomile, Roman | Coumarin constituents | Anticoagulant |
| Chondroitin | Chondroitin sulfate B (dermatan sulfate) has anticoagulant properties. Chondroitin sulfate is a component of the antithrombotic danaparoid sodium | Anticoagulant |
| Clove | Eugenol- powerful inhibitor of platelet activity | Anticoagulant |
|
Danshen (Salvia miltiorrhiza) |
Inhibition of platelet aggregation and and promotion of fibrinolytic activity |
Anticoagulant
|
|
Dehydroepiandrosterone (DHEA)+ |
Fibrinolytic potential | Anticoagulant |
| Dong Quai | Coumarin constituents | Anticoagulant |
| Evening Primrose Oil | Ingibition of platelet aggregation by gamma-linoleic acid (GLA) | Anticoagulant |
| Fenugreek | Coumarin constituents | Anticoagulant |
| Feverfew | Inhibits platelet aggregation in vitro | Anticoagulant |
| Fucus | Anticoagulant action | Anticoagulant |
| Garlic (Allium sativum) | Decreased platelet aggregation | Anticoagulant |
| Ginger | Inhibition of platelet activity | Anticoagulant |
| Ginkgo | Inhibits platelet aggregation | Anticoagulant |
| Ginseng, Panax | Reduction of blood coagulation / decrease in INR |
Anticoagulant/Coagulant |
| Goldenseal | Heparin antagonist | Coagulant |
| Hores-Chesnut | Coumarin constituents | Antocoagulant |
| Horseradish* | Peroxidase stimulates synthesis of arachidonic acid metabolites | Anticoagulant |
| Liquorice | Inhibition of platelet activity | Anticoagulant |
| Meadowsweet | Salicylate constituents | Anticoagulant |
| Melliot | Coumarin constituents | Anticoagulant |
| Mistletoe | Lectins- agglutinating activity | Coagulant |
| Poplar | Salicylate constituents | Anticoagulant |
| Prickly Ash, Northern | Coumarin constituents | Anticoagulant |
| Prickly Ash, Southern | Coumarin constituents | Anticoagulant |
| Quassia | Coumarin constituents | Anticoagluant |
| Red Clover | Coumarin constituents | Anticoagulant |
| Woodruff | Coumarin constituents | Anticoagulant |
| Tonka Beans | Coumarin constituents | Anticoagulant |
| Willow | Salicylate constituents | Anticoagluant |
| Yarrow | Coagulant, in vivo | Coagulant |
* Arachidonic acid is a precursor in the biosynthesis of leukotrienes, prostaglandins and thromboxanes which influence inflammation, allergic reaction and/or platelet aggregation.
+ Although DHEA is not of plant origin, it is found in herbal sections.
| Name of Herbal Product | Effect On INR | Bleeding Reported |
| Dong Quai | Increase | No |
| Danshen (Salvia miltiorrhiza) | Increase | No |
| Garlic (Allium sativum) (high dose) | Increase | Yes, but not in patients on warfarin |
| Ginkgo (Ginkgo biloba) | Increase | Yes |
| Ginseng | Decrease | No |
Above interaction data obtained from case reports of adverse events.
Herbal Products With Unknown Effects On Coagulation and Coumadin
| Herbal Product |
|---|
| Echinacea (Echinacea spp.) |
| Glucosamine |
| Saw palmetto (Serenoa repens) |
| St. John's wort |
| Valerian (Valeriana officinalis) |
Based on a review of literature, no information was located about an effect of these herbs on coagulation. In addition, no studies evaluating the potential for these herbs to interact with warfarin were located. Their use in combination with Coumadin should therefore be approached with caution.
Numerous factors, alone or in combination, including travel. changes in diet, environment, physical state and medication may influence response of the patient to anticoagulants. It is generally good practice to monitor the patient's response with additional prothrombin time (PT)/International Normalized Ratio (INR) determinations in the period immediately after discharge from the hospital, and whenever other medications are initiated, discontinued or taken irregularly. Medications of unknown interactions with coumarins are best regarded with caution. When these medications are started or stopped, more frequent PT/INR monitoring is advisable.