Drug Interaction in Institutionalized Elderly People

Abstract

Introduction:The observation of drug interactions should be essential in geriatric pharmacotherapy, especially in frail elderly individuals. Objective: This study aims to analyze the drug interactions among elderly residents of a long-term care facility (LTCF). Method: This was an observational, cross-sectional and descriptive study of a philanthropic LTCF. All institutionalized residents were included, and daily prescriptions of continuous medications were observed. The possible interactions (major, moderate and minor) were identified using the drugs.com platform. The most frequent drug interactions were described, and their occurrence was analyzed according to sociodemographic and clinical variables. Results: The prescriptions of 89 individuals aged 60 to 102 years were analyzed. The presence of at least one major drug interaction was observed in 38 prescriptions (42.7%), moderate drug interactions in 75 (84.3%) and minor drug interactions in 43 (48.3%). Among individuals with five or more medications, the frequency of major drug interactions was 51.9%, and among those who used eight or more drugs, it was 69.8%. A significant association was observed between the occurrence of major drug interactions and longer institutionalization time (p=0.025). Associations with age groups, gender and functionality were not significant. The major drug interactions identified were amlodipine/simvastatin (9), amlodipine/phenytoin (7) and omeprazole/cilostazol (5). The drugs most often involved in higher drug interactions were amlodipine, topiramate, haloperidol, promethazine and simvastatin. Conclusion: The results show a high possibility of drug interactions with a risk of adverse events in vulnerable elderly individuals. They also reveal that the most important drug interactions were observed with drugs frequently used in clinical practice.