General Principles of Traditional Chinese Drugs
Chapter one The characters and functions of Traditional Chinese Drugs

Each drug has its own specific characters. In traditional Chinese Drug, the different characters of drugs are employed to treat diseases, rectify the hyperactivity or hypoactivity of “yin” or“yang”, and help the body restore its normal physiological functions, consequently curing the diseases and restoring health. The various characters and functions of these drugs concerning medical treatment include drugs’ properties, flavors, actions of lifting, lowering, floating and sinking, channel tropis- -m toxicity, etc. The theory of characters and functions of traditional Chinese drugs is based on the theories of “yin” and “yang”, viscera, channels and collaterals, and treatment principles of traditional Chinese drug, and has been developed and summed up throughout a long history of medical practice. This theory provides the basis for drug analysis and application.

Section 1 Properties and Flavors of Traditional Chinese Drugs

Properties and flavors are also known as four properties and five flavors. “Property” refers to the cold , hot , warms or cool nature of a drug . These properties of drugs are so sorted out according to the different actions of the drugs on the human body and their therapeutic effects .

For example , drugs which cure cold syndrome (“yang” syndrome )have a cold or cool property ,

whereas drugs which cure cold syndrome (“yin” syndrome) have a hot or warm property .

Drugs of cold and cool natures and warm and hot natures are of opposite properties. A cold- natured drug is different from a cool-natured one only in degree, and so is a warm-natured drug from a hot-natured drug. Most of the cool- or cold-natured drugs have the effects of clearing heat, purging fire, removing toxic substances, and nourishing “yin”,and are used to cure heat syndromes. On the contrary, drugs of warm and hot nature usually have the effects of dispersing cold, warming up the interior, supporting “yang”, and treating collapse, and are therefore used to treat cold syndrome. In addition to the four properties mentioned above, there is the fifth, the neutral or mild one. When a drug is neither hot nor cold in nature, it is said to be neutral . It can be used for either hot or cold syndromes. Yet, drugs of neutral nature usually tend to be either slightly hot or slightly cold. That is why drugs are generally said to be of four properties only.

“Flavors” refers to the tastes of drugs. i.e. pungent , sweet , sour , bitter , salty , tasteless and astringent. Since sweet and tasteless usually coexist, and since sour and astringent drugs have the the same effects, pungent, sweet, sour, bitter and salty tastes are the cardinal flavors and are habitually known as five flavors. Drugs of different flavors and different compositions show different pharmacological and therapeutic action, while drugs of the same taste usually have similarities in effect and even in composition. The flavors don’t necessarily refer to the real tastes of the drugs. Sometimes they are sorted out according to drugs’ actions other than tastes. Therefore, the flavors of some drugs described in books on material medical are often different from their true tastes. Various flavors have different effects. They are explained separately as follow:

Pungent flavor: Drugs that are pungent in flavor have the effect of dispersing exopathogens from superficies of the body and promoting the circulation of the vital energy and blood. Pungent drugs are usually used for the treatment of superficial and mild illness due to affection by exopathogens, stagnation of vital energy, blood stasis, etc.

Sweet flavor: drugs of sweet flavor have the effects of nourishing, replenishing, tonifying, or

Enriching the different parts or organs of the body, normalizing the function of the stomach and spleen, harmonizing the properties of different drugs, relieving spasm and pain, etc. Drugs of sweet flavor are usually effective in treating syndromes of deficiency type, dry cough, constipation due to dry intestine, incoordination between the spleen and the stomach, various, pains, etc. besides, some of the sweet drugs have the effects of detoxification.

Sour flavor: drugs of sour flavor have the effects of including astringency and arresting discharge. Sour drugs are often used to treat sweating due to debility, chronic cough, chronic diarrhea, emission, spermatorrhea, enuresis, frequent micturition, chronic leukorrhagia, metrorrhagia or metrostaxis, etc.

Bitter flavor: drug of bitter flavor have the effects of clearing heat, purging fire, sending down the adverse flow of “qi” to treat cough and vomiting, relaxing the bowels, eliminating dampness, etc. Such drugs are mostly used for syndromes of pathogenic fire, cough with dyspnea, vomiting, constipation due to heat of excess type, damp-heat syndrome, or cold-damp syndrome and other syndromes.

Salty flavor: drugs of this taste have the effects of relieving constipation by purgation, and softening and resolving hard mass. Salty drugs are mostly used in treating dry stool and constipation, scrofula, goiter, mass in the abdomen, and other problems.

Tasteless flavor: drugs of this flavor have the effects of excreting dampness and including

Dieresis, and are commonly used for edema, dysuria and others.

Astringent flavor: drugs of this flavor have similar actions as those of sour flavor.

Drugs of the same flavor generally have the similar actions, and drugs of different tastes have quite different actions. Yet some drugs are the same in property, and, therefore, their effects are not all the same. Both coptis root, for instance, have the same cold property, yet coptis root is bitter in flavor while dried rehmannia root sweet. The former has the effects of clearing heat and drying dampness and is used for damp—heat and nourishing “yin” and is used for the condition of consumption of yin due to febrile diseases. Another example is the use of ephedra and peppermint，both of which have a pungent flavor. However，the property of ephedra is warm，whereas the property of peppermint is cool. The former has the effects of dispersing pathogenic wind—heat and is used to treat exterior wind—heat and is used to treat exterior wind—cold syndrome，while the latter has the effects of dispersing pathogenic wind—heat syndrome. Therefore，the property and flavor of a drug should be taken into consideration as an integrated whole. Only in this way can drugs be understood and used correctly.

Section 2

Action of Lifting ，Lowering ，Floating and Sinking

Action of lifting，lowering，floating and sinking refer to the upward，downward，outward or inward direction in which drugs tend to act on the body . Lifting means going up or standing up while lowering means just the opposite. Floating means going outward or sending to the surface,

whereas sinking means going inside or purging away. Lifting and floating drugs have upward and Outward actions and are used for elevating “yang”, relieving exterior syndromes by means of diaphoresis, dispelling superficial wind and cold, including vomiting, causing resuscitation, etc.

Lowering and sinking drugs have downward and inward actions and are used for clearing heat, purgation, promoting micturition, removing dampness, checking the exuberance of “yang”, sending down an adverse flow of qi to stop vomiting, relieving cough and asthma, improving digestion to remove stagnated food, tranquilizing the mind with heavy properties, etc. As the locations of diseases are different with some in the upper part of the body and some in the lower, some in the interior and some in the exterior, and as the tendencies of diseases are divided into upward (as with vomiting), downward (e.g. diarrhea, metrorrhagia, metrostaxis and proctoptosis), outward (e.g. spontaneous or night sweating) and inward (e.g. internal transmission of exterior syndrome), the lifting, lowering, floating and sinking actions of drugs are used in correspondence with the locations of diseases but in opposition to the tendec\ncies of diseases. Generally speaking, for the diseases located in the upper part or the exterior, it is appropriate to use lifting and floating drugs instead of the lowering and sinking. For example, for the exterior syndromes, lifting and floating drugs should be chosen. On the contrary, for the diseases located in the lower part or the interior, such as dry stool or constipation, it is proper to use lowering and sinking drugs, not the opposite. For the diseases of which the manifestations tend upward, drugs of lowering actions should be given rather than that of lifting, just as in the treatment of headache and vertigo due to hyperactivity of the liver-yang, drugs of lowering and sinking actions should be used to calm the liver and suppress hyperactivity of the liver-yang. On the contrary, for the diseases of which the manifestations tend downward, it is suitable to use lifting drugs instead of lowering drugs. For example, in the treatment of chronic diarrhea and proctoptosis due to sinking of “qi” of the middle-jiao, it is wise to choose lifting drugs to invigorate“qi” and lift yang.

The lifting, lowering, floating and sinking actions of drugs have close relationship with their properties and flavors. Most drugs which are pungent or sweet in flavor and warm or hot in property have lifting and floating actions, whereas most drugs, bitter, sour, or salty in flavor and cold or cool in property have lifting and floating actions, whereas most drugs, bitter, sour, or salty in flavor and cold or cool in property have lowering and sinking actions. The lifting, lowering, floating and sinking actions also have some relationship with the textures of drugs. Generally speaking, most of the light substances have the actions of lifting and floating. In contrast, most of the heavy drugs have the actions of lowering and sinking. However, though some drugs are light, they have lowering and sinking actions; and conversely, some heavy drugs have lifting and floating actions. In addition, the lifting, lowering, floating and sinking actions can also be influenced or even altered through the processing and the joint use of drugs. For example, lowering and sinking drugs can have lifting and floating actions after processing with wine, while lifting and floating drugs can have lowering and sinking actions after preparation with salt solution. If lifting and floating drugs are dispensed together with a great amount of lowering and sinking drugs, they may also have lowering and sinking actions; and similarly, when lowering and sinking drugs are used together with a great amount of lifting and floating drugs, they may exhibit some lifting and floating character.

Section 3 Channel Tropism

Channel tropism refers to a drug’s selective therapeutic effects on a certain part of the body.

A drug may exert obvious or specific therapeutic action on pathological changes in a certain channel (including some viscera thereof) or several channels, but with little effects on the others. For instance, among the heat-clearing drugs, some only clear the heat either in the lung channel or in the liver channel or in the heart channel, etc. Again, among the tonics, some strengthen the lung while others strengthen the spleen or the kidney.

Channel tropism is based on the theory of viscera, the theory of channels and collaterals, and is summed up according to the curing particular diseases for which a drug is effective. The human body is an organic whole in which the channels and collaterals link up with the interior and exterior and all parts of the body. A pathological change in the exterior may affect the viscera while diseases in the viscera may, in turn, find expressions in the exterior of the body. For this reason, the symptoms and signs of diseases occurring in different parts of the body can be understood systematically according to the theory of channels and collaterals. For instance, the flaring up of stomach-fire may result in swollen gum; and whenever there is stagnation of liver-qi, pain in the hypochondriac region will be present. Since the swelling and pain of the gum disappear when gypsum is administered, and hypochondriac pain relieved with the use of bupleurum root, we may infer that gypsum acts on disorders of the stomach channel and bupleurum, the liver channel, The above examples show that the theory of channel. Tropism is summed up through clinical practice.

The channel tropism theory should be associated with the theories of the four properties and five flavors, and actions of lifting, lowering, floating and sinking of drugs. Different drugs acting on the same channel have different effects owing to their different properties, flavors and actions of lifting, lowering, floating and sinking. For example, scutellaria root, dried ginger, lily bulb, and lepidium seed all act on the lung channel, but scutellaria root can clear lung-heat, dried ginger can warm lung-cold, lily bulb can be used to make up for lung deficiency, and lepidium seed is used to soothe excess syndrome of the lung. Therefore, only when attention is paid to the different aspects of a drug, can its actions be comprehensively analyzed and the drug correctly employed. Besides, according to the theory that viscera as well as channels and collaterals are physiologically related to one another, and pathologically affect one another, when there is pathological change in one channel, drugs acting on other channels should be used in addition to the prescription for the diseased channel itself. For instance, for abnormalities in the lung channel, drugs for strengthening the spleen channel should be added, and in case of hyperactivity of the liver-yang, drugs for nourishing the kidney-yin should be used at the same time.

Section 4
The Toxicity of Traditional Chinese Drugs

In books on herbal medicine, some drugs are marked with “toxic” “slightly toxic” “extremely poisonous” or “deadly poisonous”. These indicate that the therapeutic dosage of those drugs approaches the toxic dosage, or is already within the toxic dosage and overdosage may lead to toxic reaction, or the drug may give rise to severe side effects within this therapeutic dosage.

For the sake of safety, it is advisable to choose drugs and their proper dosage according to their toxicity, side effects, the patient’s constitution, age, severity and location of the disease. The dosage of extremely poisonous drugs should be strictly controlled and their overdosage should be avoided. Such drugs should be discontinued immediately after the patient has got better. Besides, the toxicity of poisonous drugs can be eliminated or lessened by means of processing, dispensing and preparation.

Some poisonous drugs have remarkable medical effects and can be chosen properly for the critical or obstinate diseases. It is based on the principle (of traditional Chinese medicine) saying: “treating the critical or obstinate diseases with poisonous drugs”, of which the prerequisite is safety.

Chapter Two

The Processing of Traditional Chinese Drugs

Drug processing is the process of treating natural drugs in accordance with the therapeutical, dispensing and pharmaceutical requirements before they are used or further made into various preparations. The processing consists of primary treatment of natural drugs and special treatment of some of them. Since most traditional Chinese drugs are natural with impurities mixed in when they are gathered, some can not be stored for a long time owing to their tendency to deteriorate, some can not be directly used because of their toxicity and drastic actions, and still some need to be treated in special ways to meet the therapeutic requirements, all drugs must be processed prior to application or preparation into various forms. Only after processing can drugs exert full therapeutic effects and their safe use be guaranteed.

Section 1 The Aim of Processing

The purposes of drug processing are as follows:

1. To eliminate or reduce the toxicity, drastic actions and side effects of some drugs. For instance, the toxicity of such drugs as Sichuan aconite root, wild aconite root, Kansui root and arisaema tuber can be lessened through processing. The very drastic purgative action of croton seed can be made milder after degreasing. Dichroa root has the side effects of emesis, but when it is used for the treatment of malaria, stir-baking it with wine can reduce its side effects.

2. To increase the efficacy of drugs, when aster root and coltsfoot flower are stir-backed with honey, the have a greater effect of nourishing the lung to arrest cough.. Honey-backed liquorice has a stronger effect of reinforcing the spleen to replenish “qi” and relieving spasm and pain. Vinegar-baked corydalis tuber has a stronger effect of relieving pain. White atractylodes rhizome stir-backed with earth has a bitter effect of reinforcing the spleen to stop diarrhea. When cyperus tuber is stir-fried with vinegar, its efficacy of smoothing the liver and regulating the circulation of “qi” is strengthened.

3. To change the character and function of drugs so as to meet the therapeutic needs. For example, dried rehmannia root is cold in property and is used to clear heat from the blood, but steamed rehmannia root becomes warm in property and is mainly used for enriching the blood. Dried fleece-flower root has the relective while the steamed is good for tonifying the liver and kidney. Dried rhubarb has strong purgative power, but this power becomes mild after processing, and if carbonized, it almost has no purgative effect but is good for stopping bleeding.

4.To facilitate decoction, preparation and preservation. Generally speaking, after being sliced, or other means of processing, herbal drugs can be decocted more conveniently, and it is easier to extract their active principles, or easier to grind and make them into different forms of medicine. Mineral or shell drugs are easier to be crushed or broken into pieces after calcining and tempering in vinegar. Some drugs need to be made dry adequately through processing so as to secure preservation and to prevent molding and decaying.

5.To get rid of impurities, non-medicinal parts and various bad tastes so as to make drugs clean, pure, and easy to admit. As a rule, only after processing can herbal drugs be used, for they are mixed with impurities and earth. The peel and villi of some herbal drugs should be scrubbed off, and the heads feet and wings of certain animal drugs should be cut off. Also, the salty and stinking or fishy smell of some water products should be rinsed off with repeated washing.

Section 2 Processing Methods

There are many methods to process drugs. They can be divided into the following categories:

1.Primary Processing

(1) Cleaning: to get rid of the impurities, earth or sand, and non-medicinal parts in the drug to make them clean and pure.

(2) Crushing or grinding: to crush drugs or break them into pieces or grind them into powder so as to facilitate further preparation and utilization.

(3) Cutting or slicing: to cut drugs, according to different requirements, into slices, segments, lumps or fiber to make drugs convenient for decoction and further processing, and also make drugs easy to be dried, preserved and prepared into various forms of medicine.

2.Water processing

Drugs processed with water are to be made clean, soft and less poisonous, and the mineral drugs are to be purified and fine. The following methods are common:

(1) Washing: washing off the earth, sand and impurities on the surface of drugs, or panning off impurities with water.

(2) Moistening: sprinkling clean water on drugs repeatedly, and then covering them with wet covering to soften them for easy cutting or slicing.

(3) Rinsing: putting drugs in clean water to rinse off their salty, stinking or fishy smells, and poisonous components so as to facilitate preparation and administration.

(4) Refining power with water: Insoluble minerals can be ground with water into fine power. This is accomplished in the following procedure. Put the crushed coarse particles of a mineral drug into a container and grind them together with water, decant the suspension, then pour in water and grind again. Repeat the process until no sediment of coarse particles left. Let the suspension collected stand for some time and then decant the supernatant water to get a precipitate, from which fine powder thus obtained is very fine and the loss is minimized.

3.Fire Processing

This is a method to process drugs directly or indirectly with fire .The common methods include parching, stir-baking with liquid, calcination, roasting in hot ashes, etc.

(1) Parching: Through parching, some components can be eliminated or destroyed so as to alter the character of a drug, to modify its irritation or side effects, or to moderate its extremely cold or dry property. By the method of parching, the smell and taste of drugs can be altered and some drugs may be endowed with a promoting action on the spleen.On the other hand, it will make the drugs easier to crunch and preserve, and their active principles easier to extract in decoction. Parching is subdivided into:a. Simple parching: to parch drugs to the required degrees without any assistant Material .The following degrees are usually achieved – parching it into yellow, parching it into brown, and parching it into charcoal. Parching it into yellow means parching the surface of a drug into yellowish color or till the drug bulges without much change inside parching it into brown means parching a drug to brown or black on the surface and yellowish inside with a burnt aroma; parching it into charcoal means parching a drug to the point that the outer layer is burned black while the inner part brown and partly carbonized with the original character remained.b. Parching with assistant material: to parch a drug with a certain amount of liquid and have the liquid infiltrate into the drug. T he aim of this processing is to alter the character of a drug, to increase its efficacy or to reduce its poisonous or side effects. The assistant liquids often used are honey, wine, vinegar, salt solution or ginger juice,hence the honey-baking, etc.

(2) Stir-baking with liquid: to stir-bake a drug with a certain amount of liquid infiltrate into the drug. The aim of this processing is to alter the character of a drug, to increase its efficacy or to reduce its poisonous or side effects. The assistant liquids often used are honey, wine, vinegar, salt solution or ginger juice, hence the honey baking, vinegar-baking, etc. The actions of drugs vary with the liquids. By honey baking, a drug’s effect of nourishing the lung to arrest cough and supplementing the spleen to replenish “qui” is improved, the drug’s character moderated, and the toxicity and side effects reduced. By wine baking, a drug’s effect of promoting the circulation of blood is increased and its side effects reduced. Vinegar-baked drugs have stronger effects of relieving the depressed liver and liver pain, and lesson the drugs, oxicity. Drugs baked with salt solution have better effects of tonifying the kidney and nourishing “yin” to reduce pathogenic fire. A drug of cold and its actions of preventing vomiting will be increased and its toxicity and side effects reduced.

(3)Calculation: to burn a drug directly or indirectly in a container to make it pure, crisp and easy to grind, so as to facilitate the extraction of its active principles by decoction, to modify its character and enhance its therapeutic by decoction, to modify its character and enhance its therapeutic effects. Mineral or shell drugs are burnt directly into a glow or dipped into vinegar or water immediately after being burnt. The latter procedure is called quenching. Some drugs which are used in charcoal form, e.g. carbonized hair and carbonized palmae bark, should be put in a sealed container to be calcined indirectly on a fire.

(4)Roasting in fresh cinders: to wrap a drug in wit paper or flour paste and roast it until its coating turns scorched so as to get rid of some of its oil and irritating components, and reduce its toxicity and side effects.

4. Processing with both Water and Fire

Some drugs are processed with both fire and water or other liquids. Usual procedures are as follows:

(1) Steaming: to heat a drug with vapor.

(2) Boiling: to boil a drug in water or other desirable liquids.

(3)Scalding: to dip a drug juicily in boiling water.

The above procedures can increase a drug’s therapeutic effects, decrease its toxicity, alter its character and make it easy to preserve.

5. Other Processing Methods

Drugs can be processed in some special ways as required, such as germination, fermentation and forestation. Germination means to let seeds sprout to a proper length and then dry them. Fermentation means that a drug is allowed to be fermented at a certain temperature. Forestation is the process to partially defat seed drugs, or to put mirabilite into a watermelon and leave the watermelon in a well-ventilated place until frostlike powder emerges on its surface.

Chapter Three

The Application of Traditional Chinese Drugs

This chapter explains the application of traditional Chinese drugs under the direction of the theories of traditional Chinese medicine and in accordance with the actual condition of diseases, the characters and functions of discussed include compatibility, contraindications, dosage and usage of drugs.

Section 1

Compatibility of Traditional Chinese Drugs

In the application of drugs, sometimes a single drug is used alone and sometimes two or more drugs are used together. Using one drug to treat the disease is called “going alone”. The combined application of two or more drugs is known as “mutual reinforcement ”, “mutual assistance”, “mutual restraint”, “mutual detoxification”, “mutual inhibition”, or “incompatibility”. The above expressions are referred to as “seven consequences” of drug application. Except “going alone”, they all deal with drug compatibility. Now they are touched upon as follows:

1.Mutual Reinforcement

Drugs of similar characters and functions are used in coordination to strengthen their effects.

2.Mutual Assistance

Drugs similar in certain aspects of their characters and functions can be used together, with one as the principal and the other or others as subsidiary, to help increase the effects of the principal.

3.Mutual Restraint

When drugs are used in combination, the toxicity and side effects of one drug can be reduced or eliminated by the other.

4.Mutual De-toxicity

One drug can lessen or remove the toxicity and side effects of the other.

5.Mutual Inhibition

When two drugs are used together, they inhibit or check each other to weaken or even lose their

original efficacy.

6.Incompatibility

When two drugs are used in combination, toxicity or side effects may result.

In a word, when two drugs are used in one prescription, they will give rise to interactions. They may coordinate each other to increase their toxicity or side effects: or contradict each other to weaken or lose their effects, or even give rise to toxicity and side effects. For this reason, when two or more drugs are needed, they should be chosen carefully according to the conditions of the patient, and the characters and functions of drugs. “Mutual reinforcement” and “mutual assistance” make drugs work in coordination and enhance their effects, and therefore, should be employed as much as possible. “Mutual restraint” and “mutual de-toxicity” can reduce or eliminate toxicity and side effects of drugs, “Mutual inhibition” and “incompatibility” will weaken efficacy of drugs, or make them lose their efficacy, or even give rise to toxic and side effects, and therefore, should be avoided.

Section 2

Contraindications of Traditional Chinese Drugs

Drugs may be harmful to the body as well as good for treatment of diseases. The harmful effects of a drug on the body and precautions in drug application are referred to as contraindications, which include contra-syndromes, incompatibility of drugs, contraindication for pregnancy, and food taboo.

1.Contra-syndromes

There are indications for each drug or each class of drugs. Diseases or syndromes other than these indications are contra-syndromes or contraindications. For instance, ephedra has the function of inducing diaphoresis and relieving asthma, and its indications are affection by exopathogenic wind-cold, anhidrosis due to exterior syndrome of excess type, and cough due to obstruction of the lung “qi”, but in case of spontaneous sweating due to exterior syndrome of deficiency type or cough due to lung deficiency, its use should be prohibited.

2.Incompatibility of Drugs in a Prescription

Incompatibility refers to the combined application of drugs, which will give rise to toxic reactions or side effects, or increase their original toxic and side effects, or cause loss of their efficacy. Ancient medical literature summarized the incompatibility into “eighteen incompatible medicaments” and “nineteen medicaments of mutual antagonism”.

(1) Eighteen incompatible medicaments: Aconite root is incompatible with panel tuber, trichosanthes fruit, fritillary bulb, ampelopsis root, bletilla tuber; liquorice incompatible with knoxia root, kansui root, genkwa flower, seaweed; veratrum root incompatible with ginseng, glehnia root, red sage root, scrophularia root, asarum root and peony root.

(2) Nineteen medicaments of mutual antagonism: Sulfur is antagonistic to crude mirabilite; mercury to arsenic; langdu root to lethargy; croton seed to morning glory seed; cloves to curcuma root; Sichuan aconite root and wild aconite root to rhinoceros horn; crystallized mirabilete to burred tuber; cinnamon bark to red halloysite; ginaehng to trogopterus dung.

However, combined applications of some of the drugs listed above are precedent in ancient and modern times. Experimental studies have shown that some of them will produce greater toxicity if given in combination and some of them will produce toxicity. So far there is yet no identical view, and further study is to be carried on. It is prudent to use them cautiously and under no circumstances should these drugs be used in combination before sound experimental basis and clinical experience are obtained.

3.Contraindication during Pregnancy

Because some drugs can harm the original “qi” of the fetus and lead to threaten abortion or even miscarriage, they should be prohibited or given cautiously pregnancy. Most of the prohibited drugs are very poisonous or drastic, such as croton seed, Chinese blister beetle, morning glory seed, knoxia root, kansui root, genkwa flower, pokeberry root, musk, burreed tuber, zedoary, leech, gradfly, etc. Drugs which should be given cautiously are usually those which remove blood stasis to restore menstruation, or relieve stagnation of “qi” or those with hot property and pungent flavor, or with lowering and sinking actions, such as peach kernel, safflower, cinnamon bark and so on. If not absolutely necessary, poisonous and drastic drugs shouldn't be used so as to avoid any adverse consequence.

4.Food Taboo (Dietetic Restraint)

In the course of treatment with drugs, food unfit for the disease or contraindication to a certain drug should be avoided or limited. In general, uncooked, cold, greasy, fishy and stinking, indigestible, and irritating food should be restrained or avoided. Nor, according to the condition of the disease, some food should be eaten in particular, For instance, for cold syndromes, hot, pungent, and greasy food; for patient with dizziness, insomnia and impetuous temperament, pepper, hot pepper, wine, garlic, etc.; for patients with indigestion due to deficiency of the spleen and stomach, fried, greasy and sticky food; for those with supportive infection on body surface, and cutaneous pruritus, fish, shrimps, crabs, and other fishy and irritating food. Ancient literature recorded that dichroa root counteracts raw scallion; rehmannia root and fleece-flower root counteract raw scallion, garlic and radish; peppermint counteracts turtle flesh; liquorice counteracts silver carp; poria is antagonistic to vinegar; glabrous greenbrier rhizome and quisqualis fruit are against tea; and honey is antagonistic to raw scallion. This information is offered for reference when using these drugs.

Section 3

Dosage of Traditional Chinese Drugs

Dosage means the amount of drugs to be used. It mainly refers to the daily amount of different drugs in this book, unless otherwise indicated, refers to an adult’s daily amount of dried drug in a decoction.

Dosage is directly related to the therapeutic effects and therefore should be properly determined. Since most of the traditional Chinese drugs are crude drugs, the range of safe dosage is wide and the dosage of drugs is not so strict as that of chemicals. Some of them, however of very drastic in nature or extremely poisonous, so the dosage of such drugs should be strictly controlled to prevent poisoning. In general, the following aspects should be considered when deciding the dosage of a drug.

1.Drug character

Drastic and poisonous drugs should be given in small dosages or gradually increased from small dosages to larger dosages. As soon as the patient’s condition improves, the dosage shall be reduced or discontinued to avoid drug poisoning or accumulative toxicity. As for ordinary drugs, the potent ones should be used in small quantities while the mild ones should be given in large dosages. Drugs of great density such as minerals or animal shells should be given in large dosages whereas light ones such as flowers, leaves, or volatile aromatic drugs, in small dosages. Those greasy and thick in tastes should be given in large amount.

2.Compatibility and Dosage Form

Generally speaking, the dosage of a drug should be larger when used alone than used in a compound recipe. And when used in bolus and powder form. Dosages of the principal drugs in a recipe should be larger than those of the subsidiaries.

3.Condition of the Disease, and Constitution and Age of the Patient

Usually, the dosage for serious conditions, emergencies and stubborn problems should be large for the strong patients and smaller for the aged, the frail, the maternal and children. As a rule, the dosage for a child over six is half the dosage for an adult’s. The dosage for one under five is a quarter, and for an infant, even smaller

Section 4

Administration of Traditional Chinese Drugs

This section covers the decoction of drugs, points for attention, and administration of the different dosage forms of drugs. Decoction is a very common form of Chinese pharmaceutical preparations. It is a liquid preparation made by boiling drugs with water or with a proper amount of other liquids (such as wine and vinegar). When preparing a decoction, drugs are put into a vessel of which the material’s chemical property is comparative stable (such as an earthenware, or an enamel, never an iron or copper pot) and then clean water is poured in to submerge all the drugs. After the drugs are soaked for 30-60 minutes, the pot with the drugs is to be placed on a fire, first quick-boiled, and then simmered. The drugs shall be decocted for a certain period of time according to the different requirements and then the liquid decoction decanted or filtered out. After that, water can be added to the same level and the pot can be simmered again. Usually from the same dose of drugs we get two or three decoctions which should be mixed and then taken in two or more times.

The amount of water used and the decocting period should be decided in line with the properties of the drugs. Diaphoretic and antipyretics should be decocted in a small amount of water and with a strong fire in a short period of time, usually 5-10 water and on a slow fire for a longer period of time, usually 30-40 minutes after boiling.

Some drugs should be dealt with individually because of their particular characters to guarantee the quality of the decoction and increase the therapeutic effects of the drugs.

1.To be decocted prior to other drugs. Because some mineral or shell drugs are so hard that their active compositions can not be extracted easily, they should be boiled for 15 minutes before others are put in. Such drugs include gypsum, oyster shell, shell of abalone, tortoise plastron, turtle shell among others.

2.To be decocted later than other drugs. Some aromatic drugs should be put in after the other drugs are boiled for 5-10 minutes and they should be boiled for only about five minutes in order to prevent the volatilization of their volatile active compositions. These drugs include peppermint, villous ammonium fruit, etc. Some purgative drugs such as rhubarb and seine leaf should also be boiled later.

3.To be decocted with wrappings. Some powder-like, sticky and villous drugs should be wrapped in a piece of gauze for decoction so that the decoction will not be turbid, irritating to the throat, or burnt at the bottom of the pot, e.g. British inula flower, Asiatic plantain seed and burnt clay-lining of kitchen range.

4.To be decocted separately. Some precious drugs such as ginseng, American ginseng, and rhinoceros horn should be decocted separately. The decoction obtained can be taken separately or mixed with the finished decoction of other drugs to avoid any waste of these precious drugs.

5.To be taken after being infused in warm boiled water or finished decoction. Drugs unsuitable for decoction should be ground into fine powder and infused with warm boiled water or finished decoction for administration, e.g. amber, pseudo-gin-seng and cinnabar. Liquid drugs such as bamboo juice and ginger juice should be taken following their infusion as wall.

6.To be melted. Some of the gluey and very sticky drugs should be melted or dissolved in boiling water or finished decoction for oral administration includes the time for administration, e.g. donkey-hide gelatin and malt sugar.

Drug administration includes the time for administration and the method of administration.

Usually one dose of decoction is given a day or for acute diseases two doses a day, taken in two or three times. For mild and chronic illnesses, twice a day in early morning and evening, while for serious and acute conditions, once every four hours. Tonics should be taken before meals, whereas drugs irritating to the stomach and intestines should be taken after meals (but not immediately before or after meals). Anthelmintics and purgatives should be taken on an empty stomach. Anti-malaria drugs should be taken prior to the attack, and sedatives and tranquilizers should be taken before bed-time. Medicine for chronic illnesses should be taken at regular time while medicine for acute diseases should be given instantly without a limitation of time. Some drugs can be boiled and taken frequently like tea.

Drug decoction is usually taken while it is warm. Decoction of drugs of cold property for heat syndrome is taken cold, while medicine of hot property for cold syndromes can be taken hot. In case of cold syndrome with pseudo-heat symptoms, it is better to take the medicine of hot property cold, and contrarily, in case of heat syndrome with pseudo-cold symptoms, hot decoction of drugs of cold property can be taken. For vomiting patients, the decoction can be concentrated and given frequently in small amount. Pill or bolus and powder should be taken with warm boiled water if no special direction is given.