Clinical Trial of Efficacy and Safety of Rengalin in the Treatment of Cough in Patients With Chronic Obstructive Pulmonary Disease

Design: multicenter, double-blind, randomized, parallel group placebo-controlled study. The study will enroll men and women (aged 40 to 80 years) with cough associated with stable chronic obstructive pulmonary disease (COPD). Subjects with COPD diagnosed more than 12 months earlier obtaining allowed basic therapy and retaining cough ≥2 points (according to cough severity scale \[CSS\]) despite their therapy should be considered as the study candidates. After signing patient information leaflet (informed consent form) to participate in the clinical study, collection of medical history and objective examination are performed, cough severity is assessed (using CSS; at baseline evaluation of diurnal and nocturnal cough the number of episodes and cough severity in the preceding day is taken into account) as well as intensity of COPD effect on the subject (САТ test), concomitant therapy is recorded, computer spirometry with evaluation of baseline FEV1/FVC and post-bronchodilator FEV1 (where respiratory function cannot be assessed, the results of the previous examination dating no more than 3 months earlier may be used). Females of childbearing potential will undergo pregnancy test. If a patient meets the inclusion criteria and does not demonstrate any of the exclusion criteria at Visit 1 (Day 1), he/she is randomized to one of 2 groups: group 1 patients will receive Rengalin at 2 tablets 3 times a day for 4 weeks; group 2 patients will receive placebo using Rengalin dosing regimen for 4 weeks. The patient will be monitored for 4 weeks (screening, randomization - before day 1, treatment - 4 weeks). During follow-up period two visits are scheduled (Visit 1 (Day 1) and Visit 2 (Week 4) at which objective examination, recording cough severity (using CSS) will be carried out, COPD effect on the subjects (САТ test) and concomitant therapy will be evaluated. At Visit 2 (after 4-week treatment period) compliance will be additionally assessed. At one of the clinical sites (Research Institute of Pulmonology, Russian FMBA), patients will be monitored for cough on a daily basis (using the WHolter™ monitor), with the data used as an additional measure to evaluate efficacy. Subjects are allowed to take basic COPD therapy and medications for their co-morbidities in the course of the study, except for the medicines listed in "Prohibited concomitant treatment".