Popular herb kava may pose liver risk, FDA says

By The Associated Press and Los Angeles Times

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WASHINGTON — The popular herbal supplement kava carries a "potential risk" of severe liver damage, the Food and Drug Administration warned yesterday.

The advisory urged kava consumers and their doctors to be on the lookout for signs of liver injury. It came three months after the FDA asked doctors to review their cases for links between kava and liver problems.

Kava ranks ninth in herbal supplements sold in the nation.

"This kind of liver damage appears to be extremely rare. But because it's severe ... we felt consumers needed to be aware of it," said Dr. Christine Taylor, the FDA's supplement chief.

The agency has not yet determined whether kava, or its use with some other supplement or medication, actually causes liver damage. It began investigating after a healthy 45-year-old woman who began using the herb suddenly required a liver transplant.

European health officials report 25 similar cases of liver toxicity, including four transplants.

As a result, sales were halted in Switzerland and France and suspended in Britain; Germany is acting to make kava a prescription drug; and Canada has urged consumers not to take kava until the safety question is settled.

In the United States, manufacturers do not have to prove dietary supplements are safe before they sell them. Unlike in other countries, regulators must prove a supplement is dangerous before it can halt sales.

Kava users should consult a doctor if they experience any possible symptoms of liver disease, the FDA said. Those include: jaundice, or yellowing of the skin or eyes; brown urine; nausea or vomiting; light-colored stools; unusual tiredness or weakness; stomach or abdominal pain; or loss of appetite.

People who already have liver problems, or who take medications that can harm the liver, should ask a doctor before taking kava, it said.

The FDA also urged doctors and consumers to report any possible kava side effects by calling 1-800-332-1088 or via the Internet at www.fda.gov/medwatch.

Kava is promoted to relieve anxiety, stress and insomnia. A member of the pepper family used as a ceremonial drink in the South Pacific, kava rings up about $68 million in annual sales in the U.S., industry groups said.

The FDA said kava is sold under a variety of names, including: ava, awa, intoxicating pepper, kava root or pepper, kawa, kew, Piper methysticum, rauschpfeffer, sakau, tonga, wurzelstock and yangona.

Phil Harvey, chief scientist for the National Nutritional Foods Association, which represents 3,000 retailers and 1,000 manufacturers, said the industry wants to get to the bottom of any potential risks.

In other health-related news:

• Vioxx: The popular painkiller has been linked to five cases of a nonbacterial type of meningitis, a possible side effect that — although rare — is serious, the FDA said. A spokeswoman for the drug's maker, Merck, noted that about 52 million Vioxx prescriptions have been written in the U.S. since June 1999.

• Stem cells: Embryonic stem cells have been nurtured for the first time into tiny blood vessels, researchers at the Massachusetts Institute of Technology said. If the technique is refined, scientists may eventually be able to make in the laboratory blood vessels that could replace diseased arteries.

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