Dangers of unregulated herbal therapy

A Case Report in this week's issue of The Lancet highlights the dangers of unregulated herbal therapy.

Chris Laing, Sally Hamour (Whittington Hospital, London, UK), and colleagues describe the diagnosis and treatment of a 30 year-old Chinese man who was referred to their kidney clinic in July 2003 after passing blood in his urine. The patient had been taking the Chinese herb Longdan Xieganwan to ‘enhance' his liver for at least 5 years. The doctors found that the patient had a bladder tumour, which they surgically removed. However, he developed recurrent tumours in his bladder, despite stopping his use of Chinese herbs. He has since developed kidney failure, and when the doctors saw him in June 2006, he was preparing for dialysis.

Longdan Xieganwan contains Caulis aristolochia manshuriensis of which aristolochic acid is an active ingredient. One study linked cumulative doses of aristolochic acid exceeding 200 g with bladder cancer.

Dr Laing and Dr Hamour state: "Aristolochic acid has been banned in many countries but continues to be available on the internet. This case emphasises the importance of an adequate environmental and dietary history in uronephrological disease and highlights the dangers of unregulated herbal therapy."

In an accompanying Editorial, The Lancet states that the potential benefits of indigenous herbal remedies should not be ignored but evidence is needed to prove their effectiveness: "All complementary medicines, like any medicine, have the potential for side-effects, drugdrug interactions, and contamination (especially if a herbal product). They all need regulation as drugs. And practitioners in this field need reminding, again, that they need to produce high-quality evidence of efficacy: fully powered double-blind randomised trials with relevant endpoints and sufficient follow-up, and systematic reviews."