[Effect of nafamostat mesilate on the renin-aldosterone system]

It has been reported that continuous intravenous infusion of nafamostat mesilate (FUT) produces hyperkalemia due to reduced urinary excretion of potassium. The present study was performed to see whether renin-aldosterone effect is involved in this inhibition of potassium excretion. Ten patients were studied who had been given this drug (4 mg.hr-1) to prevent postsurgical pancreatitis or DIC. Urine potassium output decreased significantly from 44 +/- 5 microEq.min-1 prior to administration of FUT to 18 +/- 4 microEq.min-1 in 3 hours, sodium/potassium ratio increased significantly from 1.7 +/- 0.7 prior to administration of FUT to 5.4 +/- 3.3 in 5 hours; and plasma aldosterone decreased significantly from 92 +/- 24 pg.ml-1 prior to administration of FUT to 63 +/- 22 pg.ml-1 in 6 hours. The results suggest that hyposecretion of aldosterone may be one of the main causes of hypokalemia. Reduced secretion of aldosterone may be due to other factors than the suppression of renin-angiotensin system.