Factors associated with drug interactions in elderly hospitalized in high complexity hospital.

This study aims to determine the frequency of potential drug-drug interactions (PDI) in hospitalized elderly and associated factors. This is a cross-sectional study in a teaching hospital. The dependent variable was the occurrence of potential drug interactions identified using DrugReax software. Patients with adverse drug reactions (ADR) related to clinical manifestations of PDIs were also identified. Multivariate logistic regressions was performed to analyze the association between the occurrence of PDIs and independent variables. In total, 237 older adults were included in the study. The prevalence of PDIs and interaction-related ADRs was 87.8% and 6.8%, respectively. The multivariate analysis showed a positive association between the detection of PDIs (OR 8.6; 95% CI, 2.5-30.0), and hospitalization due to a diagnosed circulatory system disease and number of medications > 14 (OR 9.8; 95% CI, 2.8-34.3%). The study showed a high prevalence of PDIs in the drug treatment of the elderly, but a lower prevalence of ADRs, as well as a positive association between PDIs and hospitalization due to a diagnosed circulatory system disease and number of medications > 14. The identification of factors associated with PDIs guides prevention measures for people that are more exposed to adverse events.