Potential Drug-Drug Interactions with Antimicrobials in Hospitalized Patients: A Multicenter Point-Prevalence Study

Abstract

Background: Improper use of antimicrobials can cause adverse drug events and high costs. The purpose of this study was to investigate the frequency and potential drug-drug interactions associated with antimicrobials among hospitalized patients. Material/Methods: This study was conducted on the same day in 5 different hospitals in Turkey. We included patients aged (3) 18 years who received at least 1 antimicrobial drug and at least 1 of any other drug. The Micromedex (R) online drug reference system was used to control and describe the interactions. Drug interactions were classified as contraindicated, major, moderate, and minor. Results: Potential drug-drug interactions with antimicrobials were 26.4% of all interactions. Five (42%) of 12 contraindicated interactions and 61 (38%) of 159 major interactions were with antimicrobials. Quinolones, triazoles, metronidazole, linezolid, and clarithromycin accounted for 173 (25.7%) of 673 prescribed antimicrobials, but were responsible for 141 (92.1%) of 153 interactions. In multivariate analysis, number of prescribed antimicrobials (odds ratio: 2.3001, 95% CI: 1.6237-3.2582), number of prescribed drugs (odds ratio: 1.2008, 95% CI: 1.0943-1.3177), and hospitalization in the university hospital (odds ratio: 1.7798, 95% CI: 1.0035-3.1564) were independent risk factors for developing drug interactions. Conclusions: Due to risk of drug interactions, physicians should be more cautious when prescribing antimicrobials, particularly when prescribing quinolones, linezolid, azoles, metronidazole, and macrolides.