The Polypharmacy Network

Polypharmacy Prevention
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What You Should Know About Black Cohosh?
By: Joanne Jansen PharmD and Anjanette Dymerski PharmD

Many people consider herbal supplements safe since they are natural. However, even natural things can be bad for you; for example, a bite from a black widow spider is natural and not good. Always discuss any new supplements with your doctor or pharmacist before taking them to make sure they do not interact with your medications or cause worsening of a disease you have.

It is important to remember that natural supplements and vitamins are not regulated by the Food and Drug Administration (FDA). This means that there may be ingredients in the products that are not listed. There is also no guarantee that the ingredients listed on the bottle are accurate.

Black cohosh is often used for symptoms of menopause. Only a few extracts have been shown to reduce hot flashes. These extracts contain 1 mg of triterpene glycosides. Without this ingredient, it most likely will not be beneficial for reducing menopausal symptoms.

Although some people may feel that they do get some benefit from black cohosh, there are many reasons you may not want to take it. Black cohosh may interact with some drugs and change or increase their effects. For instance, black cohosh can increase the likelihood of liver damage and other drugs that may hurt the liver as well should be avoided. These drugs include, but are not limited to:
• Acetaminophen (Tylenol®)
• Amiodarone (Cordarone®)
• Carbamazepine (Tegretol®)
• Isoniazid (INH®)
• Methotrexate (Rheumatrex®)
• Methyldopa (Aldomet®)
• Niacin (Niaspan®, and non-prescription products)
• Red yeast
• DHEA (in some multivitamins)
• Kava

Black cohosh can cause problems in people with certain diseases. If you have one of the following, discuss with your doctor or pharmacist whether you should take black cohosh:
• Breast cancer, or other hormone sensitive cancers
• Kidney transplant
• Liver disease
• Protein S deficiency

Other things you should know about black cohosh:
• Tell your doctor you are taking this drug before you have surgery. You may need to stop it two weeks before surgery to prevent bleeding problems.
• Tell your doctor or pharmacist you are taking this drug before you start any new medications.
• Some side effects of black cohosh include nausea and vomiting, rash, headache, dizziness, weight gain, breast tenderness, cramping, and liver damage.
• Make sure this is not confused with blue cohosh, which can be extremely poisonous.

More information available at the Natural Products Database of The Pharmacist’s Letter.