European Barberry - Tamoxifen Citrate Interaction
Herbal: European Barberry
Also Known As: Berberis vulgaris, Agracejo, Barberry, Berberidis Cortex, Berberidis Radicis Cortex, Berberidis Radix, Berbéris Commun, Berberry, Berbis, Common Barberry, Lebanon barberry, Mountain Grape, Oregon Grape, Pipperidge, Piprage, Sauerdorn, Sow Berry, Vinettier
Drug: Tamoxifen Citrate
Brand names:
Nolvadex, Soltamox
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Jun 22, 2025
Interaction Details
Tamoxifen Citrate is classified as belonging to the following category: Cytochrome P450 3A4 (Cyp3A4) Substrates
Theoretically, European barberry might increase the levels and clinical effects of CYP3A4 substrates.
There is very preliminary evidence suggesting that berberine, a constituent of European barberry, might inhibit the CYP3A4 enzyme. Theoretically, European barberry might have a similar effect.
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
References
- Wu X, Li Q, Xin H, Yu A, Zhong M. Effects of berberine on the blood concentration of cyclosporin A in renal transplanted recipients: clinical and pharmacokinetic study. Eur J Clin Pharmacol 2005;61:567-72.
European Barberry Overview
European barberry is a shrub that is native to Asia, Europe, and North America. The root, bark, leaf, and fruit have all been used medicinally to treat a variety of gastrointestinal, musculoskeletal, respiratory, and urinary tract conditions. The primary active constituent of European barberry is berberine, a bitter alkaloid. Barberry has been shown to be a good source of certain vitamins, especially Vitamin C.
Tamoxifen Citrate Overview
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Tamoxifen is used to treat breast cancer that has spread to other parts of the body in men and women. It is used to treat early breast cancer in women who have already been treated with surgery, radiation, and/or chemotherapy. It is used to reduce the risk of developing a more serious type of breast cancer in women who have had ductal carcinoma in situ (DCIS; a type of breast cancer that does not spread outside of the milk duct where it forms) and who have been treated with surgery and radiation. It is used to reduce the risk of breast cancer in women who are at high risk for the disease due to their age, personal medical history, and family medical history.
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Tamoxifen is in a class of medications known as antiestrogens. It blocks the activity of estrogen (a female hormone) in the breast. This may stop the growth of some breast tumors that need estrogen to grow.
European Barberry - More Interactions
European Barberry interacts with 1183 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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