Consumers who have previously experienced any liver complaints should not take Black cohosh without consulting their doctor first, international health watchdogs say.

Black cohosh, an ingredient of herbal products, is commonly used to treat menopausal symptoms and is widely available in Canada. To date, liver toxicity has been reported in 49 cases worldwide, a development that has prompted regulators in Australia first, followed by the United Kingdom, to enforce labeling of all Black cohosh products. Here are the latest developments:

In Australia, 11 cases were reported at the time of the review. Five patients were hospitalized, including two who required liver transplantation. Although some reports are confounded by more than one medication or by other medical conditions, there is sufficient evidence of a causal association between Black cohosh and serious hepatitis. Products will now include this statement on the label: “Warning: Black cohosh may harm the liver in some individuals. Use under the supervision of a healthcare professional.”

. In the U.K. the Commission on Human Medicines and the Herbal Medicines Advisory Committee has concluded that all available data underlines an association between Black cohosh and risk of liver disorders. Warnings are now to be added to the labels of Black cohosh products.

. The European Medicines Agency (EMEA) and the Committee on Herbal Medicinal Products (HMPC) announced: “… a potential connection between herbal medicinal products containing Cimicifugae racemosae rhizoma (Black Cohosh, root) and hepatotoxicity.” The EMEA is advising patients to stop taking Black cohosh and consult their doctor immediately if they develop signs and symptoms suggestive of liver injury.

“If women want a natural remedy for menopause symptoms, they have a safe alternative with red clover,” says Dr. Nancy Durand, Assistant Professor, Department of Obstetrics and Gynecology, University of Toronto. “Red clover (sold as Promensil in Canada) is shown to have a rich concentration of isoflavones, components that mimic estrogen - and in several randomized clinical trials to date, this natural remedy is showing no adverse reactions at all. Red clover contains all four of the necessary isoflavones to make a difference. Soy is also a well known isoflavone, but red clover is documented to contain 10 to 20 times the quantity found in soy, making it an effective remedy for menopause symptoms.”

At Health Canada, reports regarding Black cohosh are under review. From Jan. 1, 1998, to Feb. 28, 2005, the federal government received seven reports of adverse reactions suspected of being associated with ingestion of Black cohosh. There were no reports of liver dysfunction. All of the cases involved women, aged 33 to 55 years. Some of the reactions included dizziness, rash, pruritus, edema, increased pulse rate, bradycardia, atrial fibrillation, vaginal bleeding and convulsions. Causality could not be assigned specifically to Black cohosh because most of the reports contained insufficient clinical information and lacked details on the use of concomitant medications. Health Canada released its latest advisory on August 18, 2006, advising consumers and health care practitioners of the following: Consumers should exercise caution in the use of products containing Black cohosh, and consult a health care practitioner if they have concerns about its use. Consumers should discontinue the use of products containing Black cohosh and consult a physician if they have unusual fatigue, weakness, loss of appetite, or if they develop symptoms suggestive of liver injury such as yellowing of the skin or whites of the eyes, dark urine or abdominal pain. Unlike the recent announcements in the United Kingdom and Australia, Health Canada does not require products carrying Black cohosh to carry warning labels.

Health care providers and the public are encouraged to report any suspected adverse reactions to natural health products directly to Health Canada.

Credit: www.newscanada.com

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