Effect of conventional hemodialysis on the apixaban plasma concentration

Purpose: Apixaban is a factor Xa inhibitor used in patients undergoing hemodialysis treatment. The objective of this study is to investigate the effect of hemodialysis on apixaban plasma concentrations. Methods: This observational study is on patients treated with apixaban 2.5 mg twice daily on conventional hemodialysis with standard low-molecular-weight heparin (LMWH) anticoagulation (nadroparin 3800–7600 IU). Plasma blood samples were collected before starting dialysis (t1), 2 h after starting dialysis (t2), and directly after dialysis (t3). Apixaban concentration was measured before and after dialysis. Anti-Xa activity was measured for all three samples. Results: A significant difference was observed between the apixaban concentration before and after dialysis (mean before dialysis 141.03 ng/mL; mean after dialysis 102.71 ng/mL; p = 0.003). Nonetheless, both apixaban plasma concentrations and anti-Xa levels remained within the reference range. Anti-Xa levels had a strong correlation with the apixaban concentrations (r = 0.935, p = 0.000). Thus, anti-Xa activity might be used as a surrogate for apixaban plasma concentration. Conclusion: There seems to be no need for dose adjustments of apixaban; co-administration of LMWH next to apixaban might also be unnecessary.