Introduction/Aim. Understanding the mechanisms and classification of drug interactions can significantly reduce the occurrence of adverse effects and improve compliance. The drug selection process is complex and involves the patient's individual condition, physiological status, use of other drugs, and co-existing illnesses. It is particularly challenging to choose adequate therapy for elderly individuals due to physiological changes and polypharmacy.
The aim of this paper is to highlight the importance of an individualized approach to each patient when interpreting information provided by the existing drug databases. This approach involves considering the patient's age, comorbidities, and a proper assessment of the risk-benefit ratio.
Methods. A comparative analysis of potential drug-drug interactions was conducted on a sample of 215 outpatients. The analysis was performed using Lexicomp^®, Medscape^® and Epocrates^® databases. The frequency of certain types of interactions by drug databases, the number of patients, and the distribution of interaction types by databases were determined. The frequency of drug combinations that could potentially cause serious and contraindicated interactions by databases were also determined.
Results. Based on the study, it can be concluded that there is a correlation between the number of prescribed drugs and potential interactions. According to frequency, the most common type of interaction requires therapy monitoring (type C interaction, Monitor). However, based on the severity categorization, the same drug combinations have different classifications of interactions in available databases.
Conclusion. The obtained data can provide guidance in making decisions about drug therapy choices. Patient-specific characteristics, including comorbidities, require a personalized therapeutic approach from specialists, where pharmacists play a significant role.

 Keywords: types of interactions, comparison, databases, drug-drug

Corresponding author:
Sanja Stanković
e-mail: sanjastankovic278@gmail.com