Effects of Su-Huang Antitussive Capsule on Cough Variant Asthma

Study groups:

60 patients diagnosed with CVA will be randomised into two groups as follows:

Group 1:Su-Huang antitussive capsule The patients with cough variant asthma received Su-Huang antitussive capsule (0.45g) 3 capsules Tid for 2 weeks (swallowed by warm water at 0.5-1h after each meal).

Group 2: placebo The patients with cough variant asthma received placebo 3 capsules Tid for 2 weeks (swallowed by warm water at 0.5-1h after each meal).

The study will be divided into following phases:

1. First Visit (Visit s, day -14):

   A full medical history and physical examination to be undertaken to determine whether patients meet the inclusion/exclusion criteria.

   After the informed consent has been signed, the following samples are obtained from all patients: blood samples for routine clinical laboratory tests (haematology, biochemistry and electrocardiogram, chest x-ray). A urine pregnancy test will be performed in women of childbearing potential.

   Spirometry and methacholine bronchial provocation test were performed to determined the presence of bronchial non-specific hyper-responsiveness.

2. Screening Period (day -14 to day 0, 14 Days) Patients can take medications other than corticosteroid , β2 agonist, inhaled sodium cromoglycate.

3. Second Visit (Visit 1, Week 0):

   Patients are given the Diary Card.

   A physical examination were to be performed. All laboratory tests results are obtained to determine whether patients meet the inclusion/exclusion criteria. Concurrent medication were recorded.

   Capsaicin challenge test and FENO were performed and hypertonic saline induced sputum samples for cell differential were taken from enrolled patients.

   Enrolled patients were randomized into different groups, and the study medication were dispensed.

4. During Treatment 1(Week 0 to Week 1, 7 days):

   Patients were to take study medication for 14 days and completed Diary Card for 7 days from Week 0 to Week 1.

5. Third Visit (Visit 2, Week 1):

   A physical examination were to be performed. The Diary Card were collected and reviewed. Adverse events, secondary complications, concurrent medication will be recorded.

   The Diary Card were collected, reviewed and assessed whether treatment is efficient for cough symptom (symptom score improved 1 at least).

6. During Treatment 2 (Week 1 to Week 2, 7 days):

Patients were to take study medication for 14 days and completed Diary Card for 7 days from Week 1 to Week 2.

Spirometry and bronchial provocation test by methacholine inhalation,electro-cardiogram,capsaicin challenge test and FENO were performed and hypertonic saline induced sputum samples for cell differential were taken from enrolled patients.

Blood samples for routine clinical laboratory tests (haematology and biochemistry) were obtained, if a clinically significant laboratory abnormal result was noted at the visit 2, AE and a follow-up visit would be considered.