|Eighteen Clashes, also known as Eighteen Incompatibilities, is
an equivocal rule of Chinese medicine. It is about the prescription,
contradiction of eighteen drug pairs such as Radix Glycyrrhizae against
Radix Euphorbiae Pekinensis, Radix Aconiti against Bulbus Fritillariae
Cirrhosae, Radix et Rhizoma Veriatri Nigri against Radix Ginseng, and
so on. This rule is always followed by a majority of doctors of traditional
Chinese medicine (TCM), and is one of the major parts of the Chinese
herbal property theory. Most of the TCM doctors believe that using
anti-drugs simultaneously could generate or enhance the toxicity and
damage to human body, and thus they emphasize that the drugs which
contradict each other cannot be used in the same prescription. The
Eighteen Clashes was compiled into pithy formula and has been passed
down for nearly a thousand years since Jin Dynasty and Yuan Dynasty.
|As an important convention for drug contraindication, Eighteen
Clashes has been adopted so far and caused limited clinical applications
of anti-drugs. Nonetheless, there have been a lot of literatures on
simultaneous use of anti-drug pairs from ancient to modern times.
In the ancient formularies such as “Shang Han Lun”, “Jin Gui Yao
Lue” and “Bei Ji Qian Jin Yao Fang” authored by Zhang Zhongjing
and Sun Simiao, two famous doctors in ancient China, recorded the
prescriptions using anti-drugs, and both of these two medical scientists
had a plenty of applications of anti-drug pairs. They believed that antidrugs
could complement each other while inter-restricting. Thus there
have been quite a few successful clinical practices that using anti-drug
pairs simultaneously to treat diseases with complex pathogenesis.
Hence, whether the Eighteen Clashes should be absolutely avoided has
been continuously argued by scholars and clinicians.
|Chinese medicine is a distinct theory which was established on the
basis of thousands of year’s medical practice. It has been demonstrated
to be effective; however, some rules of it including Eighteen Clashes
have not been proved by modern science and technology. Although
many efforts have been made to explain its toxicology, Eighteen Clashes
is still unveiled. Chinese prescription is always a complex compound
containing a couple of drugs which are further classified into monarch,
ministerial, adjuvant, and guiding drugs by their specific action. These
drugs may counteract or synergize each other under certain conditions,
so it is possible that the drugs involved in Eighteen Clashes may be
against each other in one prescription but not the case in another due
to difference of composition. In addition, different organism status
has a different reaction to Chinese medicine. May be anti-drug pair is
only toxic toward an individual under certain pathological conditions,
and it may be tolerable or necessary to an individual under different
pathological conditions. In other words, certain pathological conditions
may be a necessary condition of toxicity or the foundation of the effects.
Therefore, it is not appropriate to confirm or deny the Eighteen Clashes
before the incompatibility conditions are not fully understand.
|Most of the drugs concerned in Eighteen Clashes are toxic
themselves and could result in poisoning and even fatal accident due to
overdose, improper decoction or patients with weak health conditions,
even if they are not combined with others. It has been uncertain whether
this poisoning is due to compatibility or drug toxicity itself. However,
the Eighteen Clashes has been passed down nearly a thousand years
without being abandoned or lost, there should be its raison d’etre. May
be that is to warn doctors and patients that part of the combination of
drugs could lead to some adverse reactions and side effects.
|To a certain extent, the Eighteen Clashes is explained through
ancient and modern clinical practice, pharmacological and chemical
composition research. But results are not consistent, perhaps indicating
that the Eighteen Clashes is not an absolute incompatibility. The antidrugs could benefit therapy if being used properly, and vice versa. The
research of Eighteen Clashes involves molecular biology, pharmacology,
immunology, medicinal chemistry, bioinformatics, mathematics,
computer science and so on. With fast development of contemporary
science and technology, the development and intersection of these
disciplines will provide a solid basis for scientific reveal of this time
|This work was supported by the Free Topic Project of Beijing University of
Chinese Medicine (No. 532/0100602099).