Is high-dose nafamostat mesilate effective for the prevention of post-ERCP pancreatitis, especially in high-risk patients?

Infusion of the protease inhibitor nafamostat mesilate (20 mg) effectively prevents post-ERCP pancreatitis, but only in low-risk groups. This study was performed to evaluate the use of high-dose nafamostat mesilate (50 mg) for prevention of post-ERCP pancreatitis (PEP), especially in high-risk groups. A total of 608 patients who underwent ERCP were included; 13 patients were excluded. Patients were divided into 3 groups: controls (group A), infusion with 20 mg of nafamostat mesilate (group B), or infusion with 50 mg of nafamostat mesilate (group C). The incidence of PEP was analyzed. The overall incidence of acute pancreatitis was 7.4% (44/595). There was a significant difference in the incidence of PEP with or without nafamostat mesilate (13.0% vs 4.0% and 5.1%, respectively; P < 0.0001). Subgroup analysis showed that in low-risk patients, the rate of PEP was significantly different with nafamostat (11.9% vs 2.7% and 4.0%, respectively; P = 0.007). In high-risk patients, the rate of PEP was not significantly different among treatment groups (14.6% vs 5.9% vs 6.9%, respectively; P = 0.108). Nafamostat mesilate prophylaxis (20 or 50 mg) is effective in preventing post-ERCP pancreatitis. However, the preventive effect of high-dose nafamostat mesilate (50 mg) is not significant in high-risk patients.