A prospective, two-center, open-label, randomised clinical trial assessing the efficacy and tolerability of treatment strategies involving the administration of Ergoferon and Kagocel in paediatric outpatients aged over 3 years was carried out. The study was conducted with the objective of obtaining a comprehensive evaluation of drug-based therapy options used in routine paediatric practice to treat acute respiratory infections (ARI) during the 2012-2013 epidemic season. A total of 90 ARI-diagnosed child-age patients able to initiate treatment within 48 hours of infection onset entered the trial. Nine participants were excluded from final analysis due to protocol violation. The patients were randomised into 2 groups (Ergoferon (group 1): 41 subjects and Kagocel (group 2): 40 subjects) with similar distribution of sex, age, baseline clinical data, and time of treatment initiation. The study involved clinical assessment including daily body temperature monitoring (morning/evening measurements) and three PCR assays of nasal swabs. At visits 2 and 3, the number of patients achieving normal body temperature (primary endpoint) was estimated and severity of intoxication and catarrhal syndromes and individual symptoms as well as the rate of virus elimination were evaluated. In addition, visit 3 included the assessment of the volume and cost of treatment in conjunction with clinical benefit and treatment safety/tolerability (as judged by the physicians and parents). By the end of the first day of treatment, the number of children with body temperature of above 38 С was significantly decreased as compared to the morning baseline (p=0.008) and respective values in group 2 (p=0.02). At visit 2 (treatment day 4), the state of 80% of patients in either group was assessed as satisfactory and over 70%, respectively, could maintain normal body temperature throughout the day. Total intoxication scores were reduced by 7-10 points and were less than 9 in 100% of patients. The overall scores of catarrhal symptoms were 2.5-3 points lower than the base- line levels and were less or equal to 9 in 80-90% of children in either group. By visit 3, 'satisfactory' health assessments were reported for 95% of patients in respective groups. Signs of catarrh were completely resolved in 37% of participants in group 1 and 15% in group 2 (p=0.03). At the same point, 66% of patients in group 1 and 55% in group 2 were observed to have no (or isolated or negligible) signs of infection which did not require continuation of treatment (p>0.05). The percentage of children achieving recovery was 3 times greater in group 1 than in group 2 (p=0.01). No bacterial complications were presented by any of the study subjects. The severity of individual symptoms of catarrh varied significantly between the groups as observed at visits 2 and 3. At visit 2, 92% of subjects in group 1 had no or only minor (requiring no drug intervention) obstruction breathing through the nose and 26.8% reported no nasal blockage (p=0.04), while the latter was observed to persist in 60% of children in group 2 (p<0.001). By the time of visit 2, the number of patients attaining complete resolution of serous nasal discharge was increased by more than 2.5 in group 1 - up to 31.7% (p=0.01), while this number in group 2 was 17.5% and did not significantly differ from the baseline level (visit 1, p=0.4). There were also differences in cough pattern changes between the groups, i.e. the dry cough was converted into a productive cough in 44% of subjects in group 1 vs. 20% in group 2 (p=0.06). As reported at visit 3, the number of patients having no difficulty breathing nasally was 88% in group 1 vs. 38% in group 2 (p=0.008). The percentage of children exhibiting complete resolution of cough as observed at visit 3 was 2 times higher in group 1 then in group 2 (respectively, 24% vs.12%; p>0.05). No adverse events related to medications used as part of the treatments administered were reported during the study. The mean CGI scores (overall safety and efficacy index) were similar between the groups: 3.5+0.6 in group 1 vs. 3.3+0.6 in group 2 (p=0.25). The percent of maximum scores was 51% and 38% in groups 1 and 2, respectively. Mean efficacy scores in patient groups were 3.9+0.6 and 3.6+0.6, respectively (p=0,036), with respective tolerability ratings represented by scores of 4.3+0.7 and 3.8+0.5 (p=0,002). The mean number of drugs prescribed was 4.7+1.0 in group 1 vs. 6.0+1.3 in group 2 (p<0.001). The percent of cases where not more than 4 medications were administered to a subject and the number of occasions when a child was prescribed to receive 6 drugs or over varied significantly between the groups and were 46% vs.10% and 27% vs. 70% , respectively (p<0.001). Similarly, there were differences in the duration of treatment with drugs belonging to distinct pharmacological groups: 6.0+1.4 vs.8.8+1.5 days (p<0.05) for antihistamines; 6.1+2.0 vs. 7.1+2.4 days (p=0.15) for decongestants; 6.0+1.1 vs.7.1+2.4 days (p=0.07) for mucolytics; and 6.9+1.4 vs. 8.4+2.3 days (p=0.04) for locally-acting anti-inflammatory and antiseptic agents, as reported for group 1 vs. group 2, respectively. The mean treatment cost per ARI case was 1353+320.2 rubles in group 1 compared to 1768+491.0 rubles in group 2 (p=0.008). Swab specimens from 76 children (41 subjects from group1 and 35 from group 2) were tested using PCR. Baseline specimens were mostly positive for rhinoviruses, influenza A(H3N2) virus, and parainfluenza virus types 2 and 3. By visit 2, virus elimination was demonstrated for 46% of cases in group 1 and 23% in group 2 (p<0.03). By the time of visit 3, the tests were indicative of virus removal for 66% of children in group 1 and 49% in group 2. Thus the antiviral drugs used as part of combination treatment of ARIs were shown to enable fast recovery and prevent the development of bacterial complications, proving to be well-tolerated. Patients in the Ergoferon group demonstrated faster resolution of ARI symptoms and shorter elimination of respiratory viruses, had less need for additional medications, and required 23% less spending on treatment, resulting in a greater number of favorable assessments of Ergoferon by both the physicians and parents.