Patients in treatment arm were given Zihua Wenfei Zhisou Granule (15 g/bag, one bag at a time, three times/day). Patients in placebo treatment arm were given Zihua Wenfei Zhisou Granule-matched placebo (15 g/bag, one bag at a time, three times/day). All treatment lasted for 14 days and no other antitussive/decongestant or bronchodilators are given to any patients. After that, there will be a follow-up 14 days after drug withdrawal.
Cough is a common symptom of respiratory medicine clinic patients, which has complex etiology and wide-ranging. Cough is usually divided into three categories by time: acute cough, subacute cough and chronic cough. Subacute cough has a 3~8 weeks course of disease. Its main etiology is postinfectious cough, which is mostly secondary to viral infection.The drug in this study is for post-infection cough in subacute cough. After long-term clinical practice, six traditional Chinese medicines, including Aster, Lonicera japonica, Shegan, dried ginger, mango seed and Schizonepeta tenuifolia, were selected to form Zihua Wenfei Zhisou Decoction. This product has the effect of relieving wind, relieving cough, warming the lung and resolving phlegm. It can be used for the cough syndrome caused by Wind-cold invading lungs syndrome. The aim is to evaluate the efficacy and safety of Zihua Wenfei Zhisou Granule in the treatment of postinfection cough (wind-cold lung syndrome) with placebo as a control.