Inclusion Criteria:  Patients of either gender aged 12 to 18 years. Diagnosis of ARVI based on medical examination: axillary temperature ≥ 37.8°C at examination + non-specific flu-like symptoms score ≥4, nasal/throat/chest symptom score ≥2. The first 24 hours after ARVI onset. Contraceptive measures by sexually active adolescents of both genders during the study. Patient information sheet (informed consent form) signed by one parent/adoptive parent of the patient and there is also a signed patient information sheet (informed consent form) for children aged 14 and over.  Exclusion Criteria:  Clinical symptoms of severe influenza/ARVI requiring hospitalization. Positive SARS-CoV-2 (COVID-19/Coronavirusdisease2019) antigen test. Suspected pneumonia, bacterial infection (including otitis media, sinusitis, urinary tract infection, meningitis, sepsis, etc.) requiring administration of antibiotics from the first day of illness. Suspected initial manifestations of diseases with symptoms similar to ARVI at onset (other infectious diseases, flu-like syndrome at the onset of systemic connective tissue diseases, and other pathology). Patients requiring antiviral medication prohibited within the study. Medical history of primary and secondary immunodeficiency. Medical history/suspicion of oncology of any localization (except for benign neoplasms). Aggravation or decompensation of chronic diseases (diabetes mellitus, infantile cerebral paralysis, cystic fibrosis, primary ciliary dyskinesia, bronchopulmonary dysplasia, respiratory and ENT congenital defects, etc.) affecting a patient's ability to participate in the clinical trial. Malabsorption syndrome, including congenital or acquired lactase or other disaccharidase deficiency, galactosemia. Allergy/ hypersensitivity to any component of the study drugs used in the treatment. Pregnancy. Breast-feeding. Use of medications specified in the section "Prohibited Concomitant Therapy" within two weeks prior to inclusion in the study. Patients whose parents/adopters, from the investigator's point of view, will not comply with the observation requirements during the study or follow the procedure for taking the study drugs. Medical history of mental diseases of the patient or their parent(s)/adoptive parents. Participation in other clinical trials for 3 months prior to enrollment in this study. Patient's parents/adopters who are related to any of the on-site research personnel directly involved in the study or are an immediate relative of the investigator. 'Immediate relative' means husband, wife, parent, son, daughter, brother, or sister (regardless of whether they are natural or adopted). The patient's parent/adopter who work for OOO "NPF "MATERIA MEDICA HOLDING" (i.e. the company's employees, temporary contract workers, designated officials responsible for carrying out the research or any immediate relatives of the aforementioned).