Exterior-Releasing Formulas: Pharmacological Effects & Clinical Applications
Exterior-releasing formulas induce perspiration, release exterior factors from the skin and muscles, and/or promote the eruption of measles. This method of treatment is known as han fa (sweating), one of the ba fa (eight treatment methods) described in the Huang Di Nei Jing (Yellow Emperor’s Inner Classic) in the first or second century A.D.
While exterior-releasing formulas have a wide range of clinical applications, they are primarily used to treat various respiratory and infectious disorders.
- Cough: Many exterior-releasing formulas have antitussive effects to suppress cough. Ma Huang Tang (Ephedra Decoction) arrests stubborn coughing that manifests after recovery from an exterior condition. Ma Huang Xing Ren Gan Cao Shi Gao Tang (Ephedra, Apricot Kernel, Licorice, and Gypsum Decoction) alleviates coughing and dyspnea in cases of asthma or respiratory tract infection. As an active ingredient in both formulas, Ku Xing Ren (Semen Armeniacae Amarum) has an inhibitory effect on the respiratory center of the brain, thereby producing antitussive and antiasthmatic effects.
- Wheezing and dyspnea: Xiao Qing Long Tang (Minor Bluegreen Dragon Decoction) and Da Qing Long Tang (Major Bluegreen Dragon Decoction) are exterior-releasing formulas used to treat wheezing and dyspnea. Several clinical studies have shown Xiao Qing Long Tang (Minor Bluegreen Dragon Decoction) to be effective in treating wheezing and dyspnea in patients with acute and chronic bronchial asthma. Other studies indicate that Da Qing Long Tang (Major Bluegreen Dragon Decoction) effectively treats wheezing and dyspnea arising from chronic tracheitis.
- Asthma: Many exterior-releasing formulas have marked antiasthmatic effects, and may be used to treat asthma. The proposed mechanisms of action include: 1) stimulating beta-adrenoceptors to achieve bronchorelaxation; and 2) inhibiting infiltration of eosinophils into the airway. Two formulas that can treat asthma are: Xiao Qing Long Tang (Minor Bluegreen Dragon Decoction) and She Gan Ma Huang Tang (Belamcanda and Ephedra Decoction).
- Bronchitis: Many exterior-releasing formulas are effective in treatment of bronchitis and related symptoms. Xiao Qing Long Tang (Minor Bluegreen Dragon Decoction) has both antibiotic and antiasthmatic effects, and is an excellent formula for treating bronchitis in both children and adults. Ma Huang Xing Ren Gan Cao Shi Gao Tang (Ephedra, Apricot Kernel, Licorice, and Gypsum Decoction) treats both acute and chronic bronchitis, with antitussive qualities to suppress cough, bronchodilating effects to relieve wheezing and dyspnea, and antiallergic influence to reduce swelling and inflammation.
- Pneumonia: Exterior-releasing formulas can treat both the cause and symptoms of pneumonia. For example, Xiao Qing Long Tang (Minor Bluegreen Dragon Decoction) and Yin Qiao San (Honeysuckle and Forsythia Powder) have antibiotic effects to treat lung infections. In addition, Xiao Qing Long Tang (Minor Bluegreen Dragon Decoction), Yin Qiao San (Honeysuckle and Forsythia Powder), and Ma Huang Xing Ren Gan Cao Shi Gao Tang (Ephedra, Apricot Kernel, Licorice, and Gypsum Decoction) address associated symptoms of pneumonia, such as aversion to cold, fever, cough, dyspnea, chest congestion, and the presence of sputum.
- Respiratory tract disorders: Exterior-releasing formulas treat various types of respiratory tract disorders. In addition to the examples listed above, indications include rhinitis, allergic rhinitis, nasosinusitis, tonsillitis, pharyngitis, and others.
- Nasal disorders: Exterior wind-releasing formulas effectively treat various nasal disorders, such as sinusitis, rhinitis, and nasal polyps. The mechanisms of action are attributed to antiallergic effects, mast cell stabilizing effects, and anti-inflammatory action, that suppress inflammation of the nasal mucosa. Two representative formulas for treatment of nasal disorders are Cang Er Zi San (Xanthium Powder) and Xin Yi San (Magnolia Flower Powder).
- Fever: Many formulas in this category have antipyretic effects to treat fever. The mechanisms of the antipyretic effects vary. Ma Huang Tang (Ephedra Decoction) and Gui Zhi Tang (Cinnamon Twig Decoction) have regulatory effects on body temperature to reduce fever. Ge Gen Tang (Kudzu Decoction) lowers body temperature by suppressing interferon-induced interleukin-1alpha production. Yin Qiao San (Honeysuckle and Forsythia Powder) has a broad spectrum of antibiotic effects to treat infection and fever.
- Common cold and influenza: Exterior-releasing formulas are frequently used to treat viral infections such as common cold and influenza, with answers to both cause and symptoms. Ge Gen Tang (Kudzu Decoction) has antiviral effects to treat infection, and antipyretic and anti-inflammatory effects to alleviate fever and muscle aches and pains. Xiao Qing Long Tang (Minor Bluegreen Dragon Decoction) is useful as both prophylaxis and treatment for influenza viral infection, since its antiviral effects stimulate and increase production of anti-influenza virus antibodies. Lastly, Yin Qiao San (Honeysuckle and Forsythia Powder) is one of the most frequently-used formulas for common cold and influenza, since it treats both the cause and symptoms of viral infection with its antibiotic, analgesic, anti-inflammatory and antipyretic activities.
- Infectious disorders: In addition to the infections listed above, exterior-releasing formulas effectively treat herpes zoster, measles, viral myocarditis, infectious meningitis, and many other disorders.
This article is taken out of Chinese Medical Herbology and Pharmacology by John Chen.
About the Author
Dr. John Chen is a recognized authority in both western pharmacology and Chinese Herbal Medicine, having combined formal training in both fields with extensive research 'on the ground' in China. He teaches at the USC School of Pharmacy, Emperor's College, Yo San University of TCM, OCOM, Five Branches, AOMA and ACTCM, and has taught numerous professional seminars across the U.S. and internationally. Dr. Chen's published works include Chinese Medical Herbology and Pharmacology (2003, AOM Press) and Chinese Herbal Formulas and Applications (2008, AOM Press) for which works he is the lead author.
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