Factors associated with potential drug-drug interactions in psychiatric inpatients

Objective The aim of this study was to investigate the prevalence and severity of potential drug-drug interactions (pDDIs) in hospitalised patients with major psychiatric disorders and to identify factors associated with their occurrence. Methods The research was designed as an observational, cross-sectional study conducted at the Clinic for Mental Disorders (CMD) 'Dr. Laza Lazarevic', Belgrade, Serbia. Medscape, Epocrates and Lexicomp bases were used to detect potential drug interactions among inpatients. Multivariate regression analysis was used to reveal risk and protective factors associated with the number of pDDIs. Results The study included 511 patients, average age 44.63 +/- 11.81 years. The average number of pDDIs per patient ranged from 5.9 +/- 4.7 (Medscape) to 8.2 +/- 5.4 (Epocrates) and 8.5 +/- 5.1 (Lexicomp). The following risk factors were identified by all three interaction checkers used: C-reactive protein, number of pharmacological subgroups, number of prescribed drugs, antibiotics, antacids, vitamins, number of associated comorbidities, route, form and dose of the drug. Conclusions When making clinical decisions to reduce drug problems, including DDIs, one should consult several interaction databases, which should be reviewed by a multidisciplinary team consisting of an experienced clinical pharmacist, physician, nurse, and so on.