ABSTRACT
A pilot study was carried out by the National Poison Unit, Gay’s and St. Thomas Hospital Trust, London to probe the frequency and severity of reports on the adverse effects of traditional medicines and food supplements. Emergency case inquiries to the unit, surveyed retrospectively (during 1983-1988) and prospectively (in 1991), showed a total of 5563 inquiries, with 657 patients (12%) presenting with symptoms at the time of initial inquiry. Links between exposure and clinical effects were found in 49 cases. Most of the cases were attributed to heavy metal exposure from Asian medicines through metal content, as a constituent of such preparations or due to contamination or adulteration of herbal formulations. The symptoms included gastrointestinal, hepatotoxic, dermatological, respiratory, and central nervous system problems. The effects, identied by the survey, were considered serious enough to cause concern and necessitated continued surveillance for health risk assessment (Perharic-Walton and Murray 1992). Increased incidence was observed in cases that were reported to the Malaysian Adverse Drugs Reaction Advisory Committee; the number of cases rose from 11 in 1997 to 23 in 1999. Approximately 37% of the 5000 cases of renal problems in Malaysia were attributed to the chronic use of traditional herbal preparations (Hussin 2001). The misconception that natural products are nontoxic and devoid of adverse effects is not limited to developing countries. According to a recent report, it also exists in highly developed countries where the general population resorts to natural products without proper awareness or information on the associated risks, particularly in the event of chronic or excessive use (UNESCO 2013).
