Table 2 Inclusion and exclusion criteria

Inclusion criteria

 Clinical diagnosis of PIC

 Pathogenic-wind invading lungs syndrome in TCM

 Baseline CSS of 2 or greater in the daytime and/or nighttime

 Cough lasting for at least 3 weeks but not more than 8 weeks

 Aged 18–65 years old

 Participant must voluntarily give written informed consent and report adverse events

Exclusion criteria

 Wheezing or rales on physical examination

 Bronchial provocation test positive

 Abnormal findings on plain chest radiograph

 Use of an angiotensin-converting-enzyme inhibitor within the past 2 months

 Presenting with heartburn or regurgitation

 Symptoms or signs of upper airway cough syndrome

 Current smoker or recent ex-smoker (giving up smoking for less than 3 months)

 Participant has severe primary disease of pulmonary, hepatic, renal, or hematological system, or other serious diseases affected the survival, such as cancer or AIDS

 ALT or AST >1.5 times of normal upper limit, abnormal serum creatine, abnormal serum Ig E, eosinophilia in the blood, white blood cell count <3× 10⁹/L or >10 × 10⁹/L/L, and/or neutrophil granulocyte >80%

 Pregnancy or lactating women, or women who have birth plan

 Allergic constitution or known to be allergic to any component in QFGKG

 Participants taking similar medicines in the last 1 month or having participated or participating in the other trials in last 3 months