Medicines Control Agency

 Medicines Control Agency,   Jul 28, 1999

Message from Professor Breckenridge, Chairman of the Committee on Safety of Medicines

28 July 1999

Dear Colleague,

Renal failure associated with Aristolochia in some Chinese Herbal Medicines.

There have been two reports recently received in the UK of patients with end-stage renal failure associated with Aristolochia, in Chinese Herbal Medicines. In both these cases the Chinese Herbal Medicine was used for the treatment of skin conditions. Renal failure was described in Belgium in 1993 where over 70 cases have been reported in association with a slimming product containing Aristolochia.

Aristolochia species are plants which have long been used in some Traditional Chinese Medicines. They contain aristolochic acids, which are genotoxic carcinogens and are associated with interstitial nephropathy. There is evidence that Aristolochia has been a contaminant of or used mistakenly instead of other plants, in particular Stephania (as in the Belgian cases) and Clematis (as in the UK cases), which themselves are not associated with such toxicity.

In 1997 Aristolochia was made a Prescription Only Medicine in order to restrict its availability. In view of the serious adverse effects, the Committee on Safety of Medicines has advised that the import, sale and supply of medicinal products containing Aristolochia should be prohibited immediately. A banning order will come into force on 28 July 1999 and will expire at the end of 27 October 1999. In the meantime, the Medicines Control Agency is consulting on a permanent order. The Medicines Control Agency is sampling and testing certain Chinese Herbal Medicines to gain information on the extent of the problem of contamination or substitution, so that appropriate provisions in respect of such medicines can be included in a permanent banning Order.

The use of Aristolochia contained in Chinese Herbal Medicines should be considered as a possible cause in patients presenting with unexplained renal failure and/or interstitial nephropathy. Patients who have any concern should be advised to consult their herbal practitioner as to the identity of the herbal medicines they have been prescribed. We have now been informed that, as a precaution, herbal practitioners and suppliers are suspending the use of ingredients whose Chinese names are Mu Tong and Fangji until appropriate quality checks are in place, because of the risk that they may contain Aristolochia.

Health professionals who suspect that one of their patients has suffered an adverse reaction to any herbal medicine should report this to the Medicines Control Agency/Committee on Safety of Medicines through the Yellow Card Scheme.