Adverse Reactions to Chinese Medicines: The Ancients Already Settled the Matter
China Medical News reporter — Jin Liang
In recent years drug adverse reactions have drawn more attention, and the phrase adverse reactions of Chinese medicines turns up often in the press. At the same time many drugs and health products carry the slogan pure herbal preparation, no toxicity or side-effects. Do Chinese medicines have adverse reactions or not?
The ancients said: every medicine has its three parts of poison
Many people hold that Chinese medicines are wholly natural, unlike Western medicines which are chemical preparations, and so have no toxicity or side-effects — they may be eaten freely and without fear. On this Professor Xie Haizhou of the Guang'anmen Hospital of the China Academy of Chinese Medical Sciences says: the common saying every medicine has its three parts of poison is right. The ancients held: Chinese medicines are poison to attack poison; with poisonous drugs to do medical work. Xie says the ancients divided Chinese medicines into greatly poisonous, normally poisonous, slightly poisonous, non-poisonous, holding: with greatly poisonous medicine treat disease — drive it down by six of ten; normally poisonous — by seven; slightly poisonous — by eight; non-poisonous — by nine. And: especially do not overuse and injure the right.
Professor Gong Shusheng of Beijing University of Chinese Medicine's herb-pharmacology department says: TCM from the start gave great weight to the toxicity of herbs. In high antiquity, knowing poisons and avoiding poisoning was a vital condition of human survival; on that basis, humans gradually came to know that certain plants, animals, and minerals could be used to treat disease. So from our earliest pharmacology canon, the Shennong Bencao Jing, Chinese medicines were classed by toxicity, that the doctor might attend to it in use.
Gong says: because TCM has long noted herbal toxicity and side-effects, in clinical use the aim has been to reduce them — by paozhi (processing) and by combining herbs — to keep efficacy at the maximum while reducing toxicity.
Gong continues: presence or absence of toxicity has long been one of the basic medicinal natures, so the clinician must attend carefully to possible toxic and side-effects. The reporter consulted five materia-medica works: Shennong Bencao Jing classes herbs by toxicity into upper, middle, lower; the other four list toxicity under qi-and-flavor. For instance, Bencao Gangmu on cucumber notes: sweet, cold, with slight toxicity.
Even pure-natural things cannot be taken at random
The current of return to nature has swept the world; Chinese medicines too are sought by more and more. Some buy at random from drug stores when ill; some chronic patients take herbs for long periods; some take herbs and health products even when not ill — all thinking Chinese medicines have no toxicity, even taken wrongly they will do no harm. Is that so?
Xie Haizhou says the chief adverse reactions to Chinese medicines are:
Toxic reaction: the drug itself is toxic and harms the body;
Side-effect: beyond the wanted therapeutic action, other unwanted action on the body;
Reaction in those of special constitution: some people are upset by a certain herb. Aristolochia toxicity (a much-watched recent case): long ago some people felt unwell on aristolochia and switched to another medicine, Xie noted;
Allergic reaction;
Drug dependence;
…
Gong Shusheng points out: past understanding of Chinese-medicine chronic, long-term, and cumulative toxicity has not been enough; further research is needed. Gong gives an example: ginkgo-leaf preparations are now sought after, but most people do not know that ginkgo leaves contain ginkgolic acid; in too-large dose or too-long use it can harm the heart. So ginkgo-leaf use should be limited. Some pick fallen leaves and steep them in water — Gong says this is very dangerous.
Gong adds: TCM dose matters very much; whether dose-per-single-take is too large or duration of use too long, the chance of toxicity rises. With strict control of dose and course, toxicity can be avoided or reduced.
Xie says: beyond overdose and long use, the chief causes of TCM adverse reactions are pattern-mismatch, wrong route, mistaken use, herbal quality, improper combination with Western drugs, breach of contraindication, the patient's own constitution.
So even pure-natural things cannot be put into the mouth at once. Else why did Shennong taste the hundred herbs at all? The wish to cure and live long is understandable, but a wrongly taken medicine carries one further from the wish.
Why have TCM adverse reactions grown?
Since TCM has long given weight to the toxicity question and long handled it well, why have the cases grown so noisy in the press in recent years?
Gong Shusheng: the quality of yinpian is a chief cause. Today the quality of yinpian is worrying: harvest season, species choice, paozhi method, storage — there are problems (secondary contamination and so on); relevant bodies should investigate and act.
Xie also mentions yinpian quality. From wild to home-grown and farm-raised, with fertilizer and pesticide use, and water-source pollution — whether these affect herbal quality and bring the rise of adverse reactions deserves study.
Director Zhang Xiaotong of the Beijing Cui Yueli Center for Traditional Medicine holds: many adverse reactions are not caused by the drug itself but by humans.
He says: the ancients in treatment held to stop when the disease is met — once well, stop the medicine. But today many — doctors included — think Chinese medicines may be taken long. This is greatly mistaken — and a chief cause of chronic, long-term, cumulative toxicity. TCM stresses biàn zhèng lùn zhì: a herb matches a pattern, not a disease. The disease-name may be the same but the Chinese medicines wholly different. So Zhang again stresses the saying every medicine has its three parts of poison: pattern-matched, it cures; pattern-mismatched, it harms life. He notes also: some TCMs today cannot do inspection-listening-asking-palpation, do not know the Eight Outlines, cannot recite the classic formulas — meeting a patient, they piece together a prescription by Western theory. How could that prescription not have side-effects?
Zhang says: Western drugs are dropped each year; TCM, with its own theory of drug use, has — though "toxic" — over more than two thousand years of practice not seen a single Chinese medicine dropped. This is precisely TCM's distinction.
Wang Wenkui, head of the Beijing Tai-Yi-He TCM Research Institute, bluntly says: TCM adverse reactions appear because (1) drug-use is wrong, and (2) fake TCMs are many; real TCMs few.
Asked, Xie said: that speaks to the level of TCM doctors. In the past, study was ten years at the cold window — hard work; today, those willing to work hard are far fewer.
Xie holds: TCM research should weight inheritance and bringing-forward equally; today the weight is on bringing-forward; inheritance is poor. Some treasures are lost. Xie says: TCM is a joining of humanistic and natural sciences; if the humanistic part is forced out, leaving only natural science, done badly, it ceases to be scientific. Asked if his decades of practice had produced adverse reactions, Xie said: very few.
All the TCM specialists interviewed said adverse reactions are not yet common at home; the question shows mainly in TCM exports. Xie says: in export, the issues are heavy-metal content over standard, certain toxic components over standard, and name-not-matching-substance. Gong holds that the over-standard question is debatable — TCMs are not eaten as food; one takes two or three doses a day; calculated thus, dose may well not exceed standard. Zhang Xiaotong: TCM has its own theory and method of use; the Western research method should not be forced upon it — letting the lab rat have the say — for the same herb cannot be eaten by everyone. Biàn zhèng lùn zhì: pattern-mismatched is naturally toxic. This is wholly normal.
Once ill, one must take medicine. Whether Chinese or Western, none should be taken at random. As a patient who knows neither, how to avoid adverse reactions?
First, do not take medicine at random. Many Chinese medicines are "non-toxic," but they are still medicines; taken wrongly, they too cause trouble. If for some reason no doctor's guidance is available, at least read the drug (and TCM health-product) leaflet carefully and see if it fits. Both Xie and Zhang note: rice is non-toxic, but eat too much and you bloat — let alone medicine.
Second, find real TCMs as much as possible.
Last, take Chinese and Western drugs separately. Xie: do not take together; space them an hour apart; Chinese medicines should be taken after meals.
In truth it is hard for the patient to avoid adverse reactions on his own — he is not a professional. If patients could all judge for themselves, the doctor could go to bed. For this reason every TCM doctor must devote himself to TCM theory and watch this gate for the patient.
Originally in China Medical News · Health Weekly, issue 159.