Safety of complementary medicines should be monitored

EDITOR,—Guy Vautier and R C Spiller report on a 32 year old man who died of hepatic failure after taking a complex Chinese herbal mixture.1 They identified one particular herb, Dictamnus dasycarpus, as the probable cause of the hepatotoxity. Recent double blind trials of a formula containing this herb, however, have failed to show any adverse effects on the liver.2 Moreover, an extensive literature search of references to this herb (which has been used for over 1000 years) has failed to link it with damage to the liver.

The authors singled out this herb as being the culprit because it is present in other Chinese herbal formulas that have been implicated in adverse events. But D dasycarpus is present in most Chinese herbal mixtures used to treat skin ailments, for which Chinese herbal medicine has become well known. Vautier and Spiller cite the herb's constituent xanthotoxins and psoralens as further evidence of its hepatotoxity, but these chemicals are found in the aerial part of the plant3 and not the root, which is recommended for use by herbalists. Flavanoids, which the authors also cite, are widely found in plants (for example, blackcurrant) and are not associated with hepatotoxity.

Both patients reported on previously are known to have had a history of jaundice,4 and thus the liver was probably compromised before treatment began. The Register of Chinese Herbal Medicine has notified all its members that treatment of any patient with a history of hepatitis should be undertaken only with constant monitoring, which must include liver function tests. In both cases mentioned here the deaths would not have occurred had the practitioners followed the register's guidelines.

The Register of Chinese Herbal Medicine is working towards government registration of trained herbal practitioners together with the compilation of a system of monographs providing data on quality assurance, safety, and efficacy. We welcome help in achieving these aims from the orthodox sector.