Following recent controversy surrounding the popular herb kava the American Botanical Council (ABC) is suggesting that consumers follow additional precautions when using the herb, used for reducing symptoms of anxiety and stress.
Recent case reports from Europe suggest a possible association of some kava products and liver problems. Regulatory officials in Germany have expressed concerns over cases of liver problems associated with kava and have notified kava manufacturers that licenses to market the herb could be withdrawn by the government, pending review of information submitted by the German kava industry.
On November 8 the German government provided an explanation for its proposal: In the past several years, there have been 24 adverse event reports (AERs) of hepatotoxicity reportedly associated with oral use of kava preparations in Germany and five in Switzerland.
In 18 cases conventional prescription or over-the-counter pharmaceutical drugs with known or potential liver toxicity were also being used, but the exact nature of the problem is not clear.
"No reports of adverse liver effects of kava have been published in the U.S.,'' said Mark Blumenthal, founder and executive director of ABC, a non-profit herbal research and education organisation. He noted that the U.S. Food and Drug Administration has now indicated that there are a small number of adverse events in its unpublished database. This was first reported in the FDA's letter to healthcare professionals on December 18.
"Despite the relatively good safety profile that kava has in the U.S., we need to take this action by the German government very seriously,'' Blumenthal added. "Germany has led the world in clinical research and rational regulation of herbal medicines. If their regulators think there's a problem, then we need to look at this situation very carefully. It is unclear what specific action Germany will take at this time,'' he said.
Blumenthal emphasised, "An expert evaluation of the medical case reports and all relevant scientific literature is needed to determine the extent of the problem and the appropriate steps for the proper labelling of kava.''
The association stressed that, together with a coalition of trade associations of the dietary supplement industry, it is currently actively engaged in evaluating the information that has been made available by the German regulatory authorities.