The Pharmaceutical Journal
Vol 269 No 7208 p128
27 July 2002

This article
Reprint
Photocopy

PDF* 35K

Medicines Control Agency proposes ban for kava-containing products

The MCA has been advised by the CSM to revoke licenses for medicines containing kava. Harriet Adcock (on the staff of The Journal) finds out why

Last week the Medicines Control Agency announced that it is to consult on a proposal to ban the supply of all medicinal products containing the herbal ingredient kava.

Meanwhile, preparations containing kava remain under voluntary withdrawal. Professor Tony Moffat, chief scientist, Royal Pharmaceutical Society, comments: "Unfortunately, there is too much risk for too little benefit. Our advice to pharmacists holds strong ... that in this interim period, pharmacists should temporarily remove stocks from their shelves."

The MCA's proposal to revoke licenses for medicines containing kava and to prohibit the sale of unlicensed products follows advice from the Committee on Safety of Medicines about the risk of liver toxicity posed by kava. Concerns were originally raised in December last year and at that time products were voluntarily withdrawn while the safety concerns were investigated (PJ, 22/29 December 2001, p876). Now, seven months later, the CSM has concluded that the risk:benefit ratio for products containing kava is not acceptable.

But why, if the CSM considers that kava's risk:benefit ratio warrants a ban, is only a voluntary withdrawal in place at the moment? When concerns were raised about the toxicity of aristolochia three years ago (PJ, 31 July 1999, p150) the CSM announced an immediate ban on the sale or supply of medicinal products containing that herb.

The banning order, which was later made permanent, followed two reports of end stage renal failure associated with use of aristolochia. For kava, the review of its safety profile was prompted by reports of 30 cases of severe hepatotoxicity reported to regulatory authorities in Germany and Switzerland.

A spokesman for the CSM explained: "In the case of aristolochia, the level of risk, considering the seriousness of the adverse reaction and the wide availability of the substance, was considered to be sufficient to warrant an emergency prohibition.

"Kava has on the whole been removed from sale and warnings have been issued to consumers about the risk of liver toxicity since December 2001. In the context of this and the seemingly rare nature of the reaction, the CSM considered that an emergency order was not necessary but that the consultation on prohibition of kava should proceed."

The proposed ban, however, has not been welcomed by everybody. Maurice Hanssen, director, Council for Responsible Nutrition (the trade association of the dietary supplement industry) believes a permanent ban would be inappropriate. "Strong label warnings could be sufficient," he says.

He sees the move by the MCA as the beginning of a series of restrictions on products "that many people have been taking quite happily for a number of years". Mr Hanssen is also unhappy about how the CSM came to its conclusions about the risk:benefit ratio for kava because, he says, it does not have figures for the level of use.

Mr Hanssen estimates that 1.2 million packs of kava products are sold in the United Kingdom each year and that the pharmacy trade is significant. "It is far bigger than the trade from health stores," he says.

A spokesman for the MCA acknowledged that the level of kava use in the UK is not clear but says that in reaching its conclusions, the CSM would have assumed widespread use.

The CSM also rejects the accusation that it has over reacted by suggesting that kava products should be banned.

"The provisional advice of the CSM is based on a careful review of the evidence for the safety and efficacy of kava. This advice — that the risks of liver toxicity outweigh the possible therapeutic benefits of kava — is consistent with the views of other regulatory authorities in Europe and worldwide."

The MCA is currently aware of 68 cases worldwide of liver problems suspected to be associated with kava. 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.

Report suspected cases

The CSM has written to health care professionals, including pharmacists, recommending that they ask patients presenting with symptoms of hepatotoxicity about use of kava, and report suspected cases to the CSM/MCA using the yellow card scheme. Dr Jo Barnes, research fellow, centre for pharmacognosy and phytotherapy, School of Pharmacy, University of London, welcomes this recommendation. "This is another example of a herbal safety concern where it has been recognised that pharmacists have a professional role to play," she says.

The consultation on the proposed ban of kava in unlicensed products will last until 27 September 2002. Once the consultation has ended the MCA will need to consider the responses before Ministers decide on whether to proceed with making the proposed prohibition order.

Until this time, it is important that consumers wanting to purchase kava-containing products are made aware of the risks. Not all retail outlets have co-operated with the voluntary withdrawal. In the weeks leading up to the CSM meeting last week, some health-food stores had put kava products back on sale and some of these were offering inducements to customers by selling kava preparations at reduced prices.

Dr Barnes, says: "Although kava has not been subject to an outright ban in this country, and although the risk of hepatotoxicity appears to be low with normal doses, in my view, any stores, including pharmacies, that continue to sell kava products at this time are acting unprofessionally to say the least. Those who do choose to continue to sell kava — and I do not support that — should at least inform consumers of the potential risk."

The MCA consultation document is expected to available on the web this week (www.mca.gov.uk).