Interaction Details

There were no interactions found between Letrozole and Calabar Bean. This does not mean the potential for an interaction does not exist, however. There is often a lack of studies and data surrounding traditional medicine, especially concerning drug interactions, so it is important to always consult your provider before making any changes to your medication regimen.


Still looking for more information about combining Letrozole and Calabar Bean? Ask Dr. Brian Staiger about it by contacting him directly.

Calabar Bean Overview

Calabar Bean Calabar bean (Physostigma venenosum) is a plant that is native to West Africa. It is known for its bean-like seeds, which are poisonous and contain a toxic alkaloid called physostigmine. The beans have been used as a source for prescription drugs containing physostigmine, a cholinesterase inhibitor. While Calabar bean has been used historically for its purported anti-inflammatory and pain-relieving properties, its use is generally not recommended as toxic effects can occur when ingested. These toxic effects can include excessive sweating, excessive salivation, nausea, vomiting, decreased blood pressure, confusion and muscle paralysis.
See More Information Regarding Calabar Bean

Letrozole Overview

  • Letrozole is used treat early breast cancer in women who have experienced menopause (change of life; end of monthly menstrual periods) and who have had other treatments, such as radiation or surgery to remove the tumor. It is also used to treat early breast cancer in women who have experienced menopause and who have already been treated with a medication called tamoxifen (Nolvadex) for 5 years. Letrozole is also used in women who have experienced menopause as a first treatment of breast cancer that has spread within the breast or to other areas of the body or in women whose breast cancer has worsened while they were taking tamoxifen. Letrozole is in a class of medications called nonsteroidal aromatase inhibitors. It works by decreasing the amount of estrogen produced by the body. This can slow or stop the growth of some types of breast cancer cells that need estrogen to grow.

See More Information Regarding Letrozole

Calabar Bean - More Interactions

Calabar Bean interacts with 193 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.

Return to the main herbal interaction checker page

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.

Ask A Pharmacist About Your Herbal Questions!

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!

Ask A Pharmacist