Research content and methods
cough symptoms, Anxiety, cough, Depression, Cough
EVENTS
(1) We will compare the starting time and effectiveness rate of duloxetine hydrochloride enteric-coated tablets vs. placebo for the reduction of cough symptoms and somatic symptoms in patients with refractory cough. We will also observe whether duloxetine hydrochloride enteric-coated tablets can relieve or control cough symptoms in patients. (2) After discontinuation of duloxetine hydrochloride enteric-coated tablets, the change pattern and effectiveness rate against cough and somatic symptoms of the two groups of patients will be compared, and will determined whether there is a continuation effect of duloxetine hydrochloride enteric-coated tablets after drug discontinuation.(3) We will compare the changes on the objective cough frequency, cough visual analog scale (VAS), cough symptom score, Leicester Cough Questionnaire (LCQ), cough evaluation test (CET), capsaicin cough sensitivity, Patient Health Questionnaire-9 (PHQ-9), Major Depression Inventory (MDI), the Generalized Anxiety Disorder-7 scale (GAD-7), Life Events Scale (LES-32), and induced sputum supernatant at each time point to explore whether duloxetine acid enteric-coated tablets further improve the quality of life and cough sensitivity of patients with refractory cough.(4) We will compare the drop-out rate and the completion rate of the treatment course in the two groups of patients to determine whether duloxetine hydrochloride enteric-coated tablets can improve the treatment adherence and success rate of patients.The first stage is a screening period of up to 3 days and a lead-in period of up to 4 days. The subjects who sign the informed consent form (ICF) will screened, and the qualified subjects will enter the lead-in period. The second stage runs from baseline to the 42nd (last) day of treatment, with follow-up visits on the 3rd, 7th, 14th, 21st, 28th, 35th, and 42nd days to observe the efficacy and safety of the test drugs. The third stage is the follow-up 1 week after treatment ends.