A Clinical Trial to Compare the Efficacy and Safety of 1-week Treatment of Intravenous N-acetylcysteine (NAC) 600 mg Twice Daily, Ambroxol Hydrochloride 30 mg Twice Daily and Placebo as Expectorant Therapies in Adult Chinese Patients With Respiratory Tract Diseases and Abnormal Mucus Secretions

This is a phase 3, multicenter, randomized, rater- and patient-blind, placebo- and active-controlled, 3-arm parallel group clinical trial. Patients will be randomized to N-acetylcysteine (NAC) or ambroxol or placebo in a 1:1:1 ratio. A total of approximately 333 patients in China will be randomized. The total study duration will be approximately 8 months including the enrolment period of approximately 7 months and the patient participation duration of 1 month or 4 weeks. Each patient will undergo a screening period of up to 1 week, a 1-week treatment period and a 2-week follow-up period. This study will be conducted in approximately 15-25 sites in China.