Potential drug interactions in polymedicated patients from Novo Hamburgo, RS, Brazil

Abstract

The life expectancy of the world population has increased, with the consequent increasing of the level of chronic degenerative diseases and the use of concomitant medications, featuring polypharmacy, leading to the risk of drug
interactions (DI). Thus, this study aimed to identify possible DI among the drugs used by polymedicated patients from Novo Hamburgo, RS, Brazil. A cross-sectional study was conducted with volunteers from a research project
during their initial interview. The socio-demographic data, the pathologies, the medicines used and their drugs interactions were evaluated. The diseases were classified according to the International Disease Code (CID-10), and medicines used by patients were classified according to the Anatomical Therapeutic Chemical standards (ATC). Drug interactions were identified and classified as recommended by literature and the Micromedex® system. Sixty-seven
patients (age 62±9 years, mostly female, 74.6%) participated in the study. 76.1% of patients were exposed to some DI. At all, 157 possible DI were identified with an average of 3.0±2.2 interactions per patient. Of these, 69.4% were classified as moderate, 19.8% severe and 10.8% mild. 51.6% DI were mediated by pharmacodynamic mechanisms, 31.9% were pharmacokinetic-related and 16.5% were mediated by both mechanisms. The most prevalent DI was between acetylsalicylic acid and hydrochlorothiazide. There was a high rate of DI among the participants of the research project. Most of the identified DI were severe or moderate and hence can bring considerable risks to patient
health. Thus, the DI can jeopardize patient safety, highlighting the importance of this matter and the need to assess and monitor drug therapy.