Black cohosh safety rep boosted by court decision
with a US District Court's dismissal of a product liability lawsuit
against two manufacturers of the herbal, and the testimony of the
plaintiff's experts.
Black cohosh is a member of the buttercup family, and is a perennial plant native to North America. It has a long history of use for by women to reduce menopausal symptoms such as hot flushes.
However fears over a rare causal link between black cohosh and liver damage have this year led to Australia's Therapeutics Goods Administration and the UK's Medicines and Healthcare Products Regulatory Agency to require warning statements to appear on product packaging, and the European Medicines Agency and Health Canada to issue public safety statements.
Since the case, known as Grant and Beck v Pharmavite and Nutraceutical Corp, was one two regarded as evidence of a probable causal relationship between black cohosh and liver damage, the September 8 decision handed down by the US District Court of Nebraska could be cause for reassessment.
The plaintiff developed autoimmune hepatitis and required a liver transplant just months after starting to use black cohosh-containing products. But at the hearing inconsistencies emerged between the testimonies given by the patient and her physician, who was retained as an expert, and the published case report.
Whilst the published case report stated that the patient did not drink alcohol, take illicit drugs, and was not taking any other medications including herbal medications, acetaminophen or non steroidal anti-inflammatory drugs.
In fact, it emerged that the woman regularly drank wine, took ibuprofen (a non-steroidal anti-inflammatory), and had been prescribed Valtrex, a drug that list liver enzyme abnormalities and hepatitis as reported adverse reactions.
It is not clear how this misreporting occurred. The patient's physician was one of the authors of the published case report. He admitted that he had never heard of black cohosh before treating the patient.
As for the other expert, Michael Corbett MD, a toxicologist, the court found that he had not conducted animal or human tests on black cohosh toxicity, even though he said his opinion that there was a causal link could be tested.
"In fact, the research has consistently held to the contrary, that black cohosh is non hepatoxic," said the court ruling.
Since the court granted the defendants' motions to exclude the testimonies of both expert witnesses - and without expert testimony the plaintiffs were unable to make a prima facie face, the court granted the request for summary judgement and dismissed the complaint.
US trade body the American Herbal Products Association says it has initiated contact with the health agencies in Australia, UK, Canada and Europe "to suggest reconsideration of the relevance of this case".
In the UK, at least, it is possible that black cohosh's safety record will be reassessed.
Although the herbal sector has agreed that unlicensed black cohosh products will carry a warning from the end of next month, Penny Viner, chair of the Herbal Forum, told NutraIngredients.com that the forum has asked MHRA to review the data again next year, since it appears that the number of adverse events reported is not on the increase but if anything is decreasing.
She said the MHRA "has indicated that it will".
