Prevalence and predictors of potential drug-drug interactions

Objectives. The objective of this study was to estimate the prevalence of potential drug-drug interactions (DDIs) among outpatients of city region Novi Sad, Serbia, and to investigate predictors of potential DDIs. Methods. Cross-sectional prescription database study was conducted. In the analysis were randomly included 10% outpatients with polypharmacy (n=4467), who visited Health Center over 1-month period (November 1-30, 2011). All drug combinations with potential for clinical significant DDIs were identified, according to Drug Interaction Facts by David S Tatro. A logistic regression analysis was conducted to examine patient and drug therapy characteristics as predictors of potential DDIs. Results. The prevalence of clinical significant potential DDIs was 33.31%. Odds of exposure were the highest among those aged 65 years or older (odds ratio (OR)=5.204; 95% confidence interval (CI) 2.694-10.052, p<0.001), those with ≥ 4 diagnosed diseases (OR=4.451; 95% CI 3.349-5.914, p<0.001), and those who used ≥ 5 drugs (OR= 5.735; 95% CI 4.876-6.747, p<0.001). Chronic diseases as well as their therapy also presented predictors of DDIs. Conclusion. Approximately one-third of outpatients living in Novi Sad were exposed to potential DDIs. Based on the present results could be defined recommendations for the management potential clinical significant DDIs. © 2014 Versita and Springer-Verlag