Clinical and laboratory investigations in herbal poisonings.

Herbs have been used world-wide, particularly in Chinese society, for thousands of years. Conceptually, herbs are usually considered to be non-toxic by the general public due to their natural origin. However, the consumption of herbs is well-known to be capable of producing prominent adverse health effects. Due to increased morbidity and mortality, poisonings associated with the use of herbs have raised universal attention in the last few years. In daily practice, herbs are dispensed by health professionals, quacks and other non-medical professionals, such as witch doctors, for either therapeutic or tonic purposes. Upon exposure, the clinical toxicity may vary from mild to severe and may even be life-threatening. In the clinical setting, the difficulties involved in handling the poisonings associated with the use of herbs can be categorized as follows: (1) difficulties in the identification of the proprietary substances and active ingredients; (2) problems with characterizing the kinetic pattern and toxicological effects; and (3) the uncertainty of the treatment. A systematic approach, including both clinical and laboratory investigations, is required in handling cases of herbal poisonings. Critical factors for the clinical investigation are the observation and documentation of clinical symptoms and signs, as well as the collection of information concerning prescription, packaging, herbal residues, herbal samples, amount consumed and the processing methods of the herbs. A geographically and culturally oriented data bank of analytical systems should be created to assist in the future laboratory diagnosis of herbal poisonings.