Clinical trial of the efficacy and safety of moguisteine in patients with cough associated with chronic respiratory diseases.

This completely randomised, double-blind, placebo-controlled, multicentre trial was carried out to evaluate the antitussive activity and safety of a 200 mg t.i.d. regimen of moguisteine (20 mg/ml ready-to-use suspension) during four days in patients with cough associated to chronic respiratory disorders. A total of 87 patients were enrolled, 42 on moguisteine and 45 on placebo. All had persistent dry or slightly productive coughs associated with chronic respiratory disorders. Seventy three were submitted to per protocol efficacy analyses, and eighty-three to intention-to-treat efficacy analyses. All the patients who were administered the study drug were analysed for safety. The underlying disorders reported as being associated with the target symptom were chronic obstructive pulmonary disease, cough of unknown aetiology, respiratory tract malignant neoplasms and pulmonary fibrosis. The treatment groups appeared to have been homogeneous on admission. The number of coughs in the interval 8-10 a.m. on day four vs day one was reduced by 42% on moguisteine against 14% on placebo; the difference between treatments was statistically significant (p = 0.028). The mean percent reduction of ladder scale scores of cough frequency vs baseline was greater on moguisteine than on placebo both in the day-time (especially on days one and two), and at night. The antitussive activity of moguisteine did not show remarkable variations either by diagnosis or by type of cough (dry/slightly productive). No serious adverse events were reported. No changes/trends were identified in laboratory tests that might indicate functional or toxic effects of moguisteine on specific organs.