Monarch drug: Being an essential ingredient in a prescription, it plays a leading curative role aiming at the cause or the main syndrome of a disease. Minister drug: helps strengthen the curative effect of the monarch drug.

Take Mahuang Tang for example to explain the above principle of for mulation. This recipe is composed of Mahuang (Herba Ephedrae) 9 g, Guizhi (Ramulus Cin namomi) 6 g, Xingren (Semen Armniacae Amarum) 6 g, and Gancao (Radix Glycyrrhizae) 3 g. It is used to treat exterior excess syndrome due to affection of exogenous pathogenic wind-cold, marked by aversion to cold, fever, headache, general aching, anhidrosis, asthma, thin and whitish fur, superficial and tense pulse. The syndrome herein is caused by exogenous wind-cold. Its chief syndrome is attack of wind-cold on the superficies, the accompanying one being the obstruction of the lung-qiThus the therapy for expelling cold to relieve exterior syndrome and facilitating the flow of lung-qi to relieve asthma should be employed. The first two ingredients of this recipe are both pungent in flavor and warm in property, capable of expelling cold to relieve the exterior syndrome. But Mahuang (Herba Ephedrae) bears a drastic efficacy with a large dosage, and is thus used as monarch drug to dealWith the cause of the disease and the chief syndrome (Ramulus Cinnamomi) helps Mahuang (Herb Epheadrae) induce sweating to disperse cold and expel exterior pathogenic factors and functions as minister drug. Xingren (Semen Armeniacae Amarum) acts as adjuvant drug with the function of descending adversely rising qi, stopping cough and relieving asthma, and is specially supposed to treat accompanying symptoms. The last ingredient in this recipe can mediate drug properties on the one hand, belonging to a mediating drug of guiding drugs. On the other hand, it is sweet in flavor and mild in property, and can alleviate excessive diaphoretic effects induced by the first two ingredients that are pungent and warm in nature, so it is concurrently the adjuvant drug.
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