en botanicals and warfarin sodium. Due to a lack of manufacturing standardization with botanical medicinal preparations, the amount of active ingredients may vary. This could further confound the ability to assess potential interactions and effects on anticoagulation. It is good practice to monitor the patient’s response with additional PT/INR determinations when initiating or discontinuing botanicals.
Specific botanicals reported to affect warfarin sodium therapy include the following:
Bromelains, danshen, dong quai (Angelica sinensis), garlic, Ginkgo biloba, ginseng, and cranberry products are associated most often with an INCREASE in the effects of warfarin sodium.
Coenzyme Q10 (ubidecarenone) and St. John’s wort are associated most often with a DECREASE in the effects of warfarin sodium.
Some botanicals may cause bleeding events when taken alone (e.g., garlic and Ginkgo biloba) and may have anticoagulant, antiplatelet, and/or fibrinolytic properties. These effects would be expected to be additive to the anticoagulant effects of warfarin sodium. Conversely, other botanicals may have coagulant properties when taken alone or may decrease the effects of warfarin sodium.
Some botanicals that may affect coagulation are listed below for reference; however, this list should not be considered all-inclusive. Many botanicals have several common names and scientific names. The most widely recognized common botanical names are listed.
*
Contains coumarins, has antiplatelet properties, and may have coagulant properties due to possible vitamin K content.
†
Contains coumarins and salicylates
‡
Contains coumarins and has fibrinolytic properties.
§
Contains coumarins and has antiplatelet properties.
¶
Has antiplatelet and fibrinolytic properties.
Botanicals that contain coumarins with potential anticoagulant effects:
Agrimony* Celery Passion Flower
Alfalfa Chamomile (German and Roman) Prickly Ash (Northern)
Angelica (Dong Quai) Dandelion§ Quassia
Aniseed Fenugreek Red Clover
Arnica Horse Chestnut Sweet Clover
Asafoetida Horseradish Sweet Woodruff
Bogbean† Licorice§ Tonka Beans
Boldo Meadowsweet† Wild Carrot
Buchu Nettle Wild Lettuce
Capsicum‡ Parsley
Cassia§
Miscellaneous botanicals with anticoagulant properties:
Bladder Wrack (Fucus) Pau d' arco
Botanicals that contain salicylate and/or have antiplatelet properties:
Agrimony* Dandelion§ Meadowsweet†
Aloe Gel Feverfew Onion¶
Aspen Garlic¶ Policosanol
Black Cohosh German Sarsaparilla Poplar
Black Haw Ginger Senega
Bogbean† Ginkgo Biloba Tamarind
Cassia§ Ginseng (Panax)¶ Willow
Clove Licorice§ Wintergreen
Botanicals with fibrinolytic properties:
Bromelains Garlic¶ Inositol Nicotinate
Capsicum‡ Ginseng (Panax)¶ Onion¶
Botanicals with coagulant properties:
Agrimony* Mistletoe
Goldenseal Yarrow
Effect on Other Drugs
Coumarins may also affect the action of other drugs. Hypoglycemic agents (chlorpropamide and tolbutamide) and anticonvulsants (phenytoin and phenobarbital) may accumulate in the body as a result of interference with either their metabolism or excretion.
Considerations for Increas
