从麻黄用量揣度仲景表里用药心法

Zhongjing's Idea of Drug Use for Exterior and Interior Syndrome From the Perspective of the Dosage of Mahuang( Herba Ephedrae)

麻黄汤证纯属表寒;大青龙汤证除有表寒外,尚有里热、烦躁。而麻黄汤方药纯以麻黄、桂枝、杏仁、甘草解表宣肺;大青龙汤方药在麻黄、桂枝、杏仁、甘草、生姜、大枣解表宣肺、辛散和营的基础上,尚有石膏清里热、除烦躁,且方中石膏是一变量。仲景之麻黄汤、桂枝汤,虚实各有偏重,虚实的掌握也相当科学,基本达到了比例、量化的水平,如桂枝麻黄各半汤、桂枝二麻黄一汤。而单纯解表、解表清里之麻黄汤、大青龙汤,层次递进分明。解表时分虚实,由表及里又是一个表里渐进、表里参差分明的过程。方药有其固有的作用,但用之于人,药物的疗效如何,除取决于组方中药物之间的相互作用、药物剂型、给药途径、生物利用度等,方药的剂量尤是一重要环节,而药物的剂量尤和机体因素密切相关,如何全面的、辨证的、动态的把握经方用量,无疑是安全、有效使用经方的重要内容。故而,从经方主药用量的变化揣度仲景用药心法实有裨益。

Syndrome of Ephedra Decoction pertains to exterior cold syndrome; syndrome of Major Green Dragon Decoction involves exterior cold syndrome combined with intenal heat and dysphoria. In Ephedra Decoction,Mahuang（ Herba Ephedrae）,Guizhi（ Ramulus Cinnamomi）,Xingren（ Semen Armeniacae Amarum） and Gancao（ Radix et Rhizoma Glycyrrhizae） are used to disperse the exterior and the lung. In Major Green Dragon Decoction,Mahuang（ Herba Ephedrae）,Guizhi（ Ramulus Cinnamomi）,Xingren（ Semen Armeniacae Amarum）,Gancao（ Radix et Rhizoma Glycyrrhizae）,Shengjiang（ Rhizoma Zingiberis Recens） and Dazao（ Fructus Jujubae） are used to disperse the exterior and the lung and harmonize the nutrient phase; besides,Shigao（） is used to clear internal heat and dysphoria,which is a variate in the formula. This syndrome is the transition from exterior syndrome to interior syndrome. In treating excess syndrome or deficiency syndrome,Ephedra Decoction and Cinnamon Twig Decoction have different emphasis,which is very scientific,such as decoction with half Ephedra and half Cinnamon,decoction with2 proportions of Cinnamon and 1 proportion of Ephedra. Ephedra Decoction and Major Green Dragon Decoction,with pure effects of relieving the exterior,dispersing the exterior and clearing the interior,have clear progressive effects. The prescription has intrinsic action,but the effect depends on the interaction of the herbs,dosage form of the drug,administration and bioavailability.The dosage of the prescription is an important link and it is closely related with the individual factors. How to comprehensively,dialectically and dynamically master the dosage of classic formulas is the important content to apply the classic formulas in a safe and effective manner. Therefore,it is very meaningful to explore Zhongjing＇s idea of drug use from the perspective of the dosage of main herb in the classic formulas.