Germany has revoked the license of medicines containing extracts of the kava-kava plant because the drug may be linked to serious liver injury.
The Federal Institute for Drugs and Medical Devices said in a statement issued late Monday that “this medicine may cause serious side-effects to the liver and no sufficient benefit stands against these risks.”
Exempted from the ruling are homeopathic preparations that contain only very low quantities of extracts from kava-kava, a pepper plant. The institute said it had reports of 40 cases of liver damage in Germany that may be linked to medicines containing kava-kava or its ingredient kavain, including six cases in which a liver transplant was necessary and three deaths.
Kava is promoted to relieve anxiety, stress and insomnia. It has long been used as a ceremonial drink in the South Pacific; until recently its biggest danger seemed to be in drinking too much of the sedative before driving. Then, about two years ago, kava in pill form suddenly boomed, and Europe reported liver damage.
The German authority said it “is of the opinion that other drugs or measures are available for anxiety and tension conditions for which the relationship of possible benefits to risks is clearly better.”
In March, the U.S. Food and Drug Administration warned that people who have liver problems or take drugs that can harm the liver should ask a doctor before taking kava. It hasn’t yet concluded whether kava, or its use together with some other supplement or medication, is truly to blame for health problems that have come to its attention.
The FDA began investigating the herb after a previously healthy 45-year-old woman used kava and suddenly required a liver transplant.
Canada has urged consumers not to take kava until the safety question is settled, while sales have been halted in Switzerland and France and suspended in Britain.
Regulators worldwide had been closely watching for the decision from Germany, which is considered to have the most experience in overseeing herbal remedies.