There is a clear trend toward increased life expectancy and, as a result, a growing prevalence of cardiovascular diseases and a higher incidence of thromboembolic complications (TECs). Anticoagulant therapy is indicated for the treatment and/or prevention of TECs. Among the main drugs used by physicians for this purpose, warfarin (a vitamin K antagonist) holds a primary place. Warfarin is a drug with proven efficacy; it is recognized as the drug of choice for stroke prevention in patients with arrhythmias and reduces both the risk of TECs and overall mortality.

Changes in the International Normalized Ratio (INR) against the backdrop of a properly adjusted warfarin dose can sometimes be unpredictable due to numerous factors affecting the pharmacokinetics and pharmacodynamics of the drug. The use of warfarin requires regular monitoring of INR with dose adjustments, at least monthly, once the individual effective dose has been established. In daily clinical practice, especially for patients undergoing therapy for comorbidities, the need for INR control is significantly higher. Therefore, for effective and safe therapy and to prevent adverse drug reactions, it is essential to understand the potential drug interactions of warfarin with other medications, primarily with the most commonly used antibiotics (see the table "Interactions of Antibiotics with Warfarin").