More scientific study of TCM herbs needed

The suspicion that cordyceps caused Madam Chew Kim Kee to develop extensive bleeding in the brain after surgery last year, leading to her death, has led to misconceptions about traditional Chinese medicine (TCM) and its pharmacological effects on patients ("Cordyceps 'likely led to post-op bleeding'"; May 27, and "How safe is herbal medicine?"; June 14).

Let us look at the matter from a more scientific aspect.

Cordyceps has only three main active ingredients, and adenosine (0.05 per cent to 0.18 per cent) is one of them. The study of the pharmacokinetics of adenosine in some medical journals indicates that its plasma half-life is less than 10 seconds. This means that it will clear from the blood in about 30 seconds and is unlikely to cause irreversible platelet damage ("Active ingredient doesn't last long" by Dr Koh Chin Aik; June 2).

It is doubtful whether a few pieces of cordyceps could have had such a fatal effect, especially since they were taken a week before Madam Chew's operation.

Every single herb may have a few biological active compounds.

Radix notoginseng (tianqi), for example, has diverse and opposite pharmacological effects.

The biological active compound dencichine can arrest various bleeding, while ginsenoside Rb1 and ginsenoside Rg1 can inhibit platelet aggregation, or blood clotting.

So, the pharmacological effect of each active compound on users should be carefully studied and utilised.

It is naive to believe that every herb is safe to use without proper consultation and advice.

Western drugs and Chinese herbs should not be taken at the same time, as this may create undesirable effects and complications. It is necessary to educate people on the proper ways of using herbs and to avoid self-medication.

This is an opportune moment for the Government to review the existing TCM policy. More resources should be rendered to the scientific study of herbs used in TCM.

Stanley Kwok Kin Man