Source: Shanghan Lun (Treatise on Exogenous Febrile Diseases).

Ingredients:
No.1  Mahuang (Herba Ephedrae) 9 g
No.2  Guizhi (Ramulus Cinnamomi) 6 g
No.3  Xingren (Semen Armeniaccaz Amarum) 6 g
No.4  Zhigancao (Radix Glycyrrhizae Praeparatae) 3 g

Administration:
Decoct the above drugs in water for oral use.

Actions:
Inducing perspiration to relieve exterior pathogenic factors, dispersing the lung to relieve asthma.

Clinical Application:
This recipe is for exterior-excess syndrome due to exogenous wind-cold, marked by aversion to cold, fever, headache, general aching, dyspnea without perspiration, thin and whitish tongue fur, and superficial and tense pulse. It is applicable to common cold, flu, acute bronchitis, bronchial asthma and other diseases which chiefly manifest aversion to cold without perspiration, cough and dyspnea. If complicated with pathogenic dampness marked by arthralgia, heaviness of the body, add Baizhu (RiLizoma Atractylodis Macrocephalae) to eliminate dampness, thus making a new one entitled Mahuang Jiazhu Tang.

In case of mild aversion to cold but chiefly asthma, subtract Guizhi (Ramulus Cinnamoni) to make a recipe entitled San’ao Tang specially for dispersing the lung to relieve asthma. In case of serious aversion to cold without perspiration and general aching body accompanied by dysphoria due to interior heat, double the dosage of Mahuang (Herba Ephedrae) to enhance the petency of inducing perspiration for eliminating the pathogenic factors and add Shigao (Gypsum Fibrosum ) to clear away the interior heat, called Da Qinglong Tang.

Elucidation:
The syndrome is due to attack of wind-cold on the exterior, obstruction of defensive qi, stagnation of interstitial space, and failure of pulmonary qi to disperse. It should be treated by inducing perspiration to expel pathogenic factors from the exterior and dispersing the lung to relieve asthma. In this recipe, ingredient No.1 acts as the monarch drug. It is capable of inducing sweating to dispel exogenous pathogenic factors and dispersing the lung to relieve asthma. Ingredient No. 2, as the minister drug, is capable of dispersing pathogenic cold by warming the meridians. Ingredient No. 3 capable of relieving stagnant lung-qi and No. 1 serve as adjuvant drug to enhance the effect of relieving cough and asthma. The last ingredient serves as the guiding drug, capable of mediating drug properties and invigorating qi and enriching mid-energizer so as to prevent ingredients No. 1 and No. 2 from inducing excessive sweating to impair the vital-qi.

Cautions:
The recipe is contraindicated for the exterior syndrome due to wind-cold with sweating because it is drastic in inducing sweating. So patients with general debility, blood deficiency and serious interior heat should use it with great caution.