Navigating the Complexities of Apixaban on INR Values: Inadvertent Lab Insights From a Real‐World Experience

Introduction An investigation of the impact of apixaban on the international normalized ratio (INR) and the frequency of its monitoring provides crucial information on the management of anticoagulation. Although the limits of prothrombin time (PT) and INR in monitoring direct oral anticoagulants (DOACs) are well known, the real‐world implications of increases in INR caused by apixaban need a reevaluation of their therapeutic importance. Aim To evaluate the impact of apixaban therapy on INR lab on real‐world INR monitoring data. Objective To assess the extent of INR elevation associated with apixaban and highlight the need for clinician education on the limited role of INR in DOAC monitoring. Method This study performed a single‐center retrospective analysis in adult patients administered apixaban for a minimum of 60 days, focusing on evaluating the frequency of the monitoring of INR and the relationship between use and INR elevation. Exclusion criteria were applied based on specific clinical conditions to refine the study population and isolate the impact of apixaban on INR values from confounding clinical factors. Result Among the 552 patients who were tested, 61.2% of them inadvertently monitored their INR lab. A total of 194 individuals met the specified inclusion criteria. Analysis revealed a substantial increase in INR values after apixaban administration (1.54 ± 2.59) compared to baseline readings (1.03 ± 0.62), with a statistically significant difference ( p < 0.001). Other investigated factors, such as age or polypharmacy, did not have a significant effect, except for bleeding and embolism. Conclusion Although it is generally not recommended to monitor INR values in apixaban patients, a mean increase of 0.58 INR value has been observed after its administration, highlighting the importance of educating healthcare professionals about this effect. There is a critical need for more research to inform the application of coagulation assays in the treatment of DOAC therapies, with the aim of optimizing patient care and outcomes.