Upper respiratory tract infections (URTI) are the most common cause of acute cough. Dry cough significantly disrupts daytime activity and night sleep and requires active treatment. Objective: efficacy and safety assessment of a new liquid dosage form of Rengalin in the treatment of cough in adults with URTI. Material and methods. We did a randomised controlled double blind trial of 344 patients (mean age 39,5±13,9 years) with the clinically established diagnosis of URTI; the duration of dry cough varied between 12 hours and 3 days. The observation time was 8 days. Primary efficacy endpoints were the percent of the patients with improvement or cough absence, cough duration (scored using a cough severity scale). Results. The improvement or cough absence after 3 days of treatment was 50 [52]% with Rengalin versus 37 [38]% with placebo (p=0,018 [p=0,011]), after 7 days of treatment – 95 [96]% and 93 [94]% respectively (p=0,42 [p=0,36]). The total duration of cough was significantly shorter with Rengalin (p=0,0024 [p=0,0019]). Within 7 days of treatment, the daily cough severity decreased to 1,0±0,9 [1,0±0,8] points with rengalin and 1,2±0,9 [1,2±0,9] points with placebo; night cough to 0,1±0,4 [0,1±0,4] points and 0,3±0,5 [0,3±0,6] points in groups, respectively (p <0,0001 [p <0,0001]). The highest efficacy of Rengalin was observed during the night (p=0,0011 [p=0,0008]). After 3-day course of the Rengalin therapy, 32[32%] of the patients were treated with ambroxol versus 41[43%] in the placebo group (p=0,08 [p=0,04]). The therapeutic efficacy in the Rengalin group (CGI-EI scale) was higher than in the placebo group (p=0,02 [p=0,02]). Rengalin didn`t increase adverse events frequency (p=0,37). Conclusion. The liquid dosage form of Rengalin was effective and well tolerated in the treatment of cough in adults with URTI.

Keywords: Rengalin, upper respiratory tract infections, cough