The UK's Medicines Control Agency (MCA) is to consider a proposed ban on the sale of the herbal remedy kava kava following a review of current scientific data on the product by the Committee on the Safety of Medicines (CSM).
The MCA's consultation on the proposed ban will last until 27 September, but in the meantime it has warned consumers to avoid taking kava kava, which has been linked to liver toxicity. The consultation document will be available on the MCA next week.
Kava kava is used in a number of products currently available in the UK and sold as anxiety or stress relievers. The MCA said that only a handful of these products were licensed drugs, the rest being sold as herbal remedies and therefore exempt from the same strict regulation.
The CSM began a review of the safety of kava kava in December 2001 following reports from Germany that the herb was potentially linked to liver problems, and concluded that the potential risks far outweighed any benefits. The herb was also voluntarily withdrawn from sale in the UK at that time, and the MCA stressed that it continued to have the support of the UK herbal products industry as its investigations continued.
Since then, MCA has been involved in identifying and gathering further data from the herbal sector and other regulatory authorities worldwide, and has so far discovered 68 cases of liver problems suspected to be associated with the herbal remedy. These include cases of liver failure resulting in six liver transplants and three deaths. There have been three reports of liver toxicity in the UK suspected to be due to consumption of kava kava, it added.
The proposed ban currently under consideration by the MCA will affect only the unlicensed kava kava products sold as herbal remedies. The CSM is, however, due to make a decision on whether to recommend the withdrawal of all licensed kava products as well, but only after consultation with the companies licensed to sell the drugs.
Professor Alasdair Breckenridge, chairman of the Committee on Safety of Medicines, said: "Given the safety concerns surrounding the use of medicinal products containing the herbal ingredient kava kava, our advice is that it would be prudent for anyone taking such products to stop taking them. There should not be any adverse effects from stopping kava kava abruptly. If anyone taking kava kava feels unwell or has concerns about possible liver problems, they should stop taking the kava kava and seek medical advice."
Since kava kava can be used as an ingredient in some foodstuffs, the Food Standards Agency (FSA) is also involved in the current process, and is to consult with experts on a proposed ban on the use of the product in foods.
The concerns over the safety of kava kava have been growing steadily this year, following mounting evidence from Germany in particular that the herb can have potentially fatal effects. A review of the same evidence from Germany carried out by a researcher in the US (commissioned, it must be said, by the supplements industry), claimed that there was no clear evidence of the dangers associated with the product, but this did not stop the US Food & Drug Administration from issuing a warning about using kava kava.
The herb has also been withdrawn from sale in Germany, France and Ireland this year alone, while authorities in Australia have also warned about the link with liver toxicity.