Cascara Sagrada - Premarin (Conjugated Estrogens) Interaction
Herbal: Cascara Sagrada
Also Known As: Frangula purshiana, Rhamnus purshiana, Bitter Bark, Buckthorn, California Buckthorn, Cascara Sagrada, Chittem Bark, Dogwood Bark, Nerprun, Pastel Bourd, Purshiana Bark, Rhamni Purshianae Cortex, Rhubarbe des Paysans, Sacred Bark, Sagrada Bark, Yellow Bark
Drug: Conjugated Estrogens
Brand names:
Premarin, Cenestin, Enjuvia, Premarin Vaginal Cream
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
May 25, 2025
Interaction Details
Conjugated Estrogens is classified as belonging to the following category: Cytochrome P450 3A4 (Cyp3A4) Substrates
Theoretically, cascara sagrada might decrease the effects of CYP3A4 substrates.
In vitro research suggests that cascara sagrada can induce CYP3A4 enzymes, albeit to a much lower degree than rifampin, a known CYP3A4 inducer.
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
- Mazzari ALDA, Lacerda MG, Milton FA, et al. In vitro effects of European and Latin-American medicinal plants in CYP3A4 gene expression, glutathione levels, and P-glycoprotein activity. Front Pharmacol 2022;13:826395.
Cascara Sagrada Overview
Cascara sagrada is a tree native to the Pacific coast of North America. The name "cascara sagrada" means "sacred bark" in Spanish.
The bark of Cascara sagrada is used in traditional medicine most commonly as a laxative as it contains anthraquinone glycosides, which stimulate the muscles in the walls of the intestines, increasing peristalsis and promoting bowel movements. It is also used as a treatment for hemorrhoids and is sometimes used as a natural remedy for liver and gallbladder problems.
Conjugated Estrogens Overview
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The estradiol cypionate and estradiol valerate forms of estrogen injection are used to treat hot flushes (hot flashes; sudden strong feelings of heat and sweating) and/or vaginal dryness, itching, and burning in women who are experiencing menopause (change of life; the end of monthly menstrual periods). However, women who need a medication only to treat vaginal dryness, itching, or burning should consider a different treatment. These forms of estrogen injection are also sometimes used to treat the symptoms of low estrogen in young women who do not produce enough estrogen naturally. The estradiol valerate form of estrogen injection is also sometimes used to relieve the symptoms of certain types of prostate (a male reproductive organ) cancer. The conjugated estrogens form of estrogen injection is used to treat abnormal vaginal bleeding that a doctor has decided is caused only by a problem with the amounts of certain hormones in the body. Estrogen injection is in a class of medications called hormones. It works by replacing estrogen that is normally produced by the body.
Cascara Sagrada - More Interactions
Cascara Sagrada interacts with 724 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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