Efficacy and Safety of Zihua Wenfei Granules in Treatment of Postinfectious Cough (Wind-cold Invading Lungs Syndrome)

Inclusion Criteria: When signing the informed consent form, the age is between 18 and 65 years old (including 18 and 65 years old)； Diagnosis of postinfectious cough; Wind-cold invading lungs syndrome in TCM Zheng; Baseline cough visual analogue scale of 60 mm or more; Cough duration of 3- 6 weeks; Voluntarily provide written and informed consent. Exclusion Criteria: Cough caused by cough variant asthma, upper airway cough syndrome, eosinophilic bronchitis, gastroesophageal reflux cough or any other concomitant conditions; Patients with severe pulmonary diseases such as lung cancer, lung tuberculosis, or lung fibrosis; After inhaling bronchodilator, patients with FEV1/FVC<70% were excluded; Subjects who have taken angiotensin-converting-enzyme inhibitor (ACEI) in the past month; Current smokers or recent ex-smokers quitting smoking less than 3 months ago; FeNO ≥ 32 ppb or Bronchial provocation test positive (for FeNO and Bronchial provocation test, if the center cannot detect it, it can be detected in other qualified tertiary hospitals); Combined with serious cardio-cerebrovascular diseases, malignant tumors, diseases of blood and hematopoietic system, gastrointestinal diseases or other serious or progressive diseases of the system; Or those who are unable to cooperate or unwilling to cooperate due to severe mental illness, severe cognitive impairment, etc; Liver and kidney dysfunction: ALT or AST >2 times the upper limit of normal reference value; And/or serum creatinine >1.5 times the upper limit of normal reference value, or eGFR< 60 mL/min/1.73m2; White blood cell count < 3.0×109/L or > 10.0×109/L, and/or neutrophil granulocyte > 80%; Patients with temperature of 37.3℃ or above; Patients taking similar medications in the last one week; Have a long history of alcohol or drug abuse; Pregnancy or potential pregnancy or lactation; Allergic constitution or known to be allergic to any component in tested drug; Patients having participated or participating in another trial in last 3 month; Patients unsuitable for clinical trials judged by researchers.