Adsorption of Nafamostat Mesilate on AN69ST Membranes: A Single‐Center Retrospective and In Vitro Study

Abstract We examined whether AN69ST (acrylonitrile and methallyl sulfonate copolymer) membranes adsorb nafamostat mesilate. This study retrospectively analyzed 87 continuous hemodiafiltration sessions in vivo. We divided the continuous hemodiafiltration sessions into AN69ST and non‐AN69ST groups using the nafamostat mesilate dose and activated clotting time as indicators of nafamostat mesilate adsorption onto the membrane. Furthermore, we studied the in vitro adsorption of nafamostat mesilate from nafamostat mesilate solutions onto four different hemodialysis membranes. This in vivo study shows that nafamostat mesilate doses were significantly higher, but activated clotting times were shorter ( P < 0.001) in the AN69ST group than in the non‐AN69ST group. These results suggest that AN69ST adsorbs nafamostat mesilate. Further, the in vitro experiments show that nafamostat mesilate adsorbs AN69ST on membranes significantly more than the other membranes tested. These in vitro and clinical findings provide evidence that AN69ST may adsorb nafamostat mesilate.