The article presents the results of a study of potential drug interactions in the treatment of moderate and severe community-acquired pneumonia (CAP) in hospital settings. The study was conducted by analysis of treatment standards and data from real clinical practice regarding antimicrobial therapy. Methods. The study used the lists of drug products for medical use for the treatment of CAP (according to the standards of specialized medical care for moderate and severe CAP with complications). Also, the medical records of patients (n = 165) with CAP, hospitalized in hospitals of medical organizations (Nizhny Novgorod) were used. The study period was 2 years (2015 - 2016). The study included all patients admitted to the hospital during the analyzed period. CAP was treated in accordance with treatment standards. Results. The analysis of potential interactions of drugs used for moderate and severe CAP according to the treatment standards, showed that 27 and 72 drugs can be used, respectively. 325 potential interactions are possible in hospital settings for moderate CAP and 2,485 for severe CAP. According to the treatment standard, the number of minimally clinically significant potential interactions during the pharmacotherapy of moderate CAP in hospital settings is 8, the number moderately clinically significant interactions - 19; undesirable interactions - 7. In case of severe CAP, the number of potential interactions increases and amounts to 27 minimally clinically significant, 105 moderately clinically significant, and 41 undesirable. The analysis of the results of antimicrobial therapy in real clinical practice showed 4 therapeutic duplications (prescribing 2 β-lactam antibacterial drugs simultaneously) and 2 moderately clinically significant interactions during antimicrobial therapy in hospital 1. Only 1 therapeutic duplication was noted during antimicrobial therapy in hospital 2. Therapeutic overlap has been found between β-lactam antibacterial drugs (ceftaroline fosamil and meropenem). It is advisable to prescribe no more than one в-lactam antibacterial drug and it is inappropriate to include > 3 antimicrobial drugs in an antimicrobial regimen. Conclusion. Electronic databases simplify the selection of medicines and thus ensure the safe and effective use of registered drug interactions.
