EDITORLocal events caused great public health concern recently. After the referral of a 44 year woman with new onset hypertension, palpitation, anxiety, and a body mass index of 19 kg/m2 it became apparent that an alarming number of the local population had been attending a particular Chinese herbalist for weight loss remedies. Most had been taking multiple preparationsas many as nineand described "spectacular" results. Several reported considerable cardiovascular symptoms but were reassured that Chinese medicines are natural and can cause no harm. We analysed the prescribed substances and the urine of several patients.

Use of aristolochia extract in Chinese medicines for weight loss has been implicated in renal failure and urogenital malignancy and is now banned. Our patients had no evidence of renal complications. We initially suspected that the preparations might contain an ephedra alkaloid (Ma Huang in Chinese medicine); the dangers and widespread use of dietary supplements containing ephedra have been highlighted.

Analysis by gas chromatography, however, showed a high concentration of fenfluramine in two of the products (sold as Qian Er and Ma zin dol) and also in the patients' urine. Subsequently a student nurse was admitted to this hospital with severe fenfluramine toxicity, which developed two hours after her first dose of a herbal slimming remedy.

After reports of an association with pulmonary hypertension fenfluramine was withdrawn even as a prescription only medicine in 1997. Its use as described is obviously illegal. Further toxicological analysis of the multiple products prescribed is ongoing: given the practice of polypharmacy, the potential for drug interaction is self evident.

This case is now under investigation by the Medicines Control Agency, which has yet to establish exactly where in the chain of supply adulteration with fenfluramine occurred. The agency recently published a report on traditional ethnic medicines and present medicines law.

The vast majority of Chinese herbalists and practitioners of other traditional medicines are responsible, professional, and caring. Our recent experience, however, highlights how the public's trend to believe, often with great naivety, in natural remedies can be abused. Stringent regulation of traditional medicines, at least to the standards of conventional practice, is urgently needed.

Karl Metcalfe, consultant physician.
　　karl.metcalfe@southend.nhs.uk

Cathryn Corns, consultant biochemist.
　　Michael Fahie-Wilson, consultant biochemist.
　　Paul Mackenzie, chief biomedical scientist.
　　Southend Hospital, Westcliff-on-Sea, Essex SS0 0RY

　　From BMJ.com