13 Aug 2004

The Medicines and Healthcare products Regulatory Agency (MHRA) wishes to remind stakeholders of its plans, as previously stated in January 2003, to review the available evidence relating to the hepatotoxicity of Kava-kava in order to assess whether the controls on Kava-kava remain justified and proportionate. As part of a public consultation exercise planned to be launched in January 2005, interested parties will be invited to submit to the Agency any evidence to support the safety of Kavakava.

Introduction

In January 2003, the Government prohibited Kava-kava in unlicensed herbal medicines following reports World-wide of idiosyncratic liver damage associated with the consumption of Kava-kava. Some of the adverse reactions reported were severe in nature.

Following advice from the Committee on the Safety of Medicines (CSM) and the Medicines Commission that Kava-kava posed a rare but serious risk to public health, Ministers prohibited the sale, supply and importation of Kava-kava for use in unlicensed herbal remedies, other than those for external use, by an Order under section 62 of Medicines Act 1968. Similar action was taken in relation to Kava-kava in foods.

In line with the principles of Best Regulation, the MHRA will review the prohibition at any time if significant new data supporting its safe use comes to light. Additionally, at the time of the prohibition Ministers specifically asked the Medicines and Healthcare products Regulatory Agency (MHRA) to undertake a review of the available evidence relating to the safety of Kava-kava, two years after the prohibition had been in place, to assess whether the prohibition remained justified.

In line with Minister’s wishes, the MHRA is planning to launch a formal 12 week public consultation exercise in January 2005.

Risk assessment

On the basis of the accumulated evidence from the UK herbal sector and regulatory authorities World-wide at the time, the CSM and the Medicines Commission advised that unlicensed medicines containing Kava-kava posed a rare but serious risk to public health.

The advisory committees considered all available data at the time and were unable to identify the mechanism of liver toxicity associated with Kava-kava or factors that would predict which individuals may be at risk of adverse reactions to Kava-kava. From the data available, a link between the onset of hepatotoxicity and dose could not be established and no other specific risk factors could be identified.

The committees therefore advised that unlicensed medicines containing Kava-kava should be removed from the market.

Type of evidence

The Agency has carefully considered several representations made by interested parties since the introduction of the prohibition in 2003. On each occasion, the MHRA concluded that evidence submitted did not add to existing understanding and that the risk assessment of Kava-kava in relation to hepatotoxicity remained unchanged.

The Agency therefore concluded that it was necessary in the interests of safety to continue to prohibit the sale, supply and importation of medicinal products containing Kavakava. Stakeholders wishing to participate in the review process may therefore wish to focus their attention on any genuinely new evidence.

Any new data permitting identification of the mechanism of toxicity, or data on any patient or product characteristics (such as dose) associated with increased risk would form an important part of the review of the existing risk assessment for Kava-kava.

The Agency is willing to provide comments on draft protocols for research projects to investigate these areas.

Timetable and process

The MHRA plans to initiate the review process in January 2005 by formally writing to interest groups. The consultation period will run for 12 weeks. All representations will be considered carefully and the advice of the Agency’s scientific advisory committees sought as appropriate.

If you have any queries about the review process, please contact myself (020 7084 2404; Room 16-132 Market Towers; alison.daykin@mhra.gsi.gov.uk). For scientific advice, including advice on draft research protocols, contact Sarah Wark (020 7084 2763; Room 14-201 Market Towers; sarah.wark@mhra.gsi.gov.uk)

Alison Daykin
Senior Herbal Policy Manager
Medicines and Healthcare products Regulatory Agency (MHRA), UK
020 7084 2404
020 7084 2387
16-132 Market Towers
1 Nine Elms Lane
London SW8 5NQ
alison.daykin@mhra.gsi.gov