Alder Buckthorn - Warfarin Interaction
Herbal: Alder Buckthorn
Also Known As: Frangula alnus, Rhamnus frangula, Alder Dogwood, Arraclán, Arrow Wood, Aulne Noir, Black Dogwood, Bois Noir, Bourdaine, Buckthorn, Dog Wood, Frángula, Frangula, Frangule, Glossy Buckthorn, Nerprun Bourdaine, Nerprun Noir
Drug: Warfarin
Brand names:
Warfarin
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
May 11, 2025
Interaction Details
Warfarin is classified as belonging to the following category: Warfarin (Coumadin)
Alder buckthorn has stimulant laxative effects. In some people alder buckthorn can cause diarrhea. Diarrhea can increase the effects of warfarin, increase international normalized ratio (INR), and increase the risk of bleeding. Advise patients who take warfarin not to take excessive amounts of alder buckthorn.
Interaction Rating
Likelihood of Occurrence
PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
Alder Buckthorn Overview
Alder buckthorn (Rhamnus frangula) is an invasive shrub native to Europe and North America. Its bark has been traditionally used in medicine due to its cathartic effects in the large intestine, attributed to its anthraglycoside content. It is generally used to help alleviate constipation. However, chronic use of alder buckthorn has been linked to gastrointestinal epithelial cell damage, pigmentation of the colonic mucosa (pseudomelanosis coli), and a potential risk of colorectal cancer. If used as a dietary supplement, the duration of use for alder buckthorn should be limited to no more than a few days altogether, due to its potential adverse effects on gastrointestinal health with prolonged use. In 1993, the FDA removed its Generally Recognized As Safe (GRAS) status due to insufficient safety data, particularly regarding prolonged use of its anthraquinone laxatives, reinforcing the need for caution in its medicinal use.
Warfarin Overview
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Warfarin is used to prevent blood clots from forming or growing larger in your blood and blood vessels. It is prescribed for people with certain types of irregular heartbeat, people with prosthetic (replacement or mechanical) heart valves, and people who have suffered a heart attack. Warfarin is also used to treat or prevent venous thrombosis (swelling and blood clot in a vein) and pulmonary embolism (a blood clot in the lung). Warfarin is in a class of medications called anticoagulants ('blood thinners'). It works by decreasing the clotting ability of the blood.
Alder Buckthorn - More Interactions
Alder Buckthorn interacts with 122 drugs
Interaction Rating Key
These severity listings are for informational use only. Never start, stop or otherwise change your therapy before speaking with your provider.
| Major | The combined use of these agents is strongly discouraged as serious side effects or other negative outcomes could occur. |
| Moderate | Use cautiously under the care of a healthcare professional or avoid this combination. A significant interaction or negative outcome could occur. |
| Minor | Be aware that there is a chance of an interaction. Watch for warning signs of a potential interaction. |
| Unknown | No interactions have been reported or no interaction data is currently available. |
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Parts of this content are provided by the Therapeutic Research Center, LLC.
DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.
© 2021 Therapeutic Research Center, LLC
Drug descriptions are provided by MedlinePlus.
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Dr. Brian Staiger, PharmD
In addition to being a clinical pharmacist specializing in pharmacotherapy, Dr. Brian Staiger is a registered herbalist through the American Herbalist Guild. He has combined his passion for pharmacy practice with the study of medical ethnobotany to improve patient care. Feel free to reach out about any of your herbal or medication questions!
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