Toxicity of complementary therapies: an eastern perspective.

Chinese traditional medicine is used extensively in Chinese populations, and other Asian countries employ similar therapies. Herbal treatments have a major role in these systems, and although most have a well-established safety record, occasional adverse effects are seen. Problems arise when toxic herbs are used in excessive doses, with improper preparation, or when they are substituted erroneously. There may also be adulteration with Western drugs or heavy metals, and interactions between herbs and Western drugs may also occur. It is always prudent to obtain a complete history of the use of herbal medications during any clinical assessment, particularly in Asian patients.