Adverse reactions and adulteration related to herbal supplements in Japan

Objective

Systematic review of adverse reactions and adulteration associated with herbal supplements in Japan.

Materials and methods

Systematic literature searches were made using the databases written in Japanese, including the reports from the Japan Medical Association and the Ministry of Health, Labour, and Welfare.

Results

In 2002, there was an outbreak of hepatic and/or thyroid dysfunctions associated with herbal supplements for weight loss. The adulteration of unapproved chemical substances caused the dysfunctions in 671 patients, including three cases of death.

In addition to this outbreak, the following substances were detected and reported in various herbal products: glibenclamide, dexamethasone, indomethacin, sildenafil citrate, bisacodyl, phenobarbital, sibutramine, hydrochlorothiazide, and ephedrine.

As adverse reactions, the following reports were found. In August 2003, there was one case report of respiratory distress after consumption of uncooked Sauropus androgynus as a supplement. Toxicological aspects of kampo, a traditional Japanese herbal medicine, were also known in clinical use. The number of case reports of adverse reactions associated with kampo medicine has been growing.

Conclusion

Many cases were found where an unknown adulterant rather than herbs caused the problems. Most of these herbal supplements were derived from outside Japan and were imported. Because of the question of quality control in some countries, it is important to develop an effective reporting system of adulteration and adverse reactions associated with herbs.