Kava-kava is a traditional herbal remedy, derived from the pepper plant. It contains Piper methysticum and is used traditionally in association with many conditions such as anxiety, insomnia and for ailments affecting the bladder and digestive tracts.

The Health Sciences Authority has obtained the agreement of all traders marketing products containing kava-kava to voluntarily withdraw and discontinue the distribution of these products in Singapore as soon as possible. This precautionary measure is being taken in the light of the serious liver side effects reported recently in Germany and Switzerland. No such adverse effects have been reported in Singapore.

To-date, we are aware of about 30 reports of liver toxicity associated with these products. Most of the reports are from Germany and Switzerland where these products are used very widely. The 30 cases of hepatoxicity varied in severity from abnormal liver function to liver failure. The onset of reaction of the adverse effect was from 2 weeks to 2 years after onset of exposure. In a number of these cases, there were other confounding factors such as concomitant drugs, which could possibly have caused the liver problems. More recently, the Germany authorities informed us of 4 cases of severe liver reaction, which required liver transplants.