Peony - Mephenytoin Interaction
Herbal: Peony
Also Known As: Paeonia lactiflora, Bai Shao, Chi Shao, Chinese Peony, Common Peony, Coral Peony, Cortex Moutan, European Peony, Jiu Chao Bai Shao, Moutan, Mu Dan Pi, Paeoniae Alba, Paeoniae Flos, Paeoniae Radix, Peonía, Peony Root, Piney, Pivoine, Pivoine Arbustive, Pivoine Blanche
Drug: Mephenytoin
Brand names:
Mesantoin
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
May 18, 2025
Interaction Details
Mephenytoin is classified as belonging to the following category: Phenytoin (Dilantin)
Theoretically, peony might reduce the levels and clinical effects of phenytoin.
Animal research shows that taking peony root reduces levels of phenytoin. Some researchers suggest that peony root might affect cytochrome P450 (CYP) 2C9, which metabolizes phenytoin. However, preliminary research in humans shows that peony root does not alter levels of losartan (Cozaar), which is also metabolized by CYP2C9.
Interaction Rating
Likelihood of Occurrence
ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
References
- Chen LC, Chou MH, Lin MF, Yang LL. Effects of Paeoniae Radix, a traditional Chinese medicine, on the pharmacokinetics of phenytoin. J Clin Pharm Ther 2001;26:271-8.
- Xie HJ, Yasar U, Sandberg M, Rane A. Paeoniae Radix, a traditional Chinese medicine, and CYP2C9 activity. J Clin Pharm Ther 2002;27:229-30. .
Peony Overview
Peonies are flowering plants that belong to the genus Paeonia, which is part of the family Paeoniaceae. They are native to Asia, Europe, and western North America. Peonies are known for their large flowers, which come in a range of colors including white, pink, red, and yellow.
Peonies, specifically the roots of the plant, have been historically used in traditional Chinese medicine (TCM) for a variety of purposes, including as an antipyretic and an anti-inflammatory agent. It has also been used as a natural remedy for anxiety and stress. The flower and seeds of the plant have also been used medicinally.
Peony - More Interactions
Peony interacts with 788 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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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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