Adverse effects associated with herbal medicine.

Medical journals are now publishing case reports of adverse reactions to herbal therapy. With increasing use, and more importantly, increasing awareness of potential hazardous effects, these reports are liable to increase in frequency. It is also increasingly realised that herbs and drugs can interact in the same way that drug/drug interactions occur. This is particularly hazardous for the patient if the treating doctor is not aware of the herbal prescription. This article reviews the published material and highlights areas of major concern. Most of the serious adverse events reported relate to problems of product quality or adulteration.