Pretreatment with nafamostat mesilate, a kallikrein inhibitor, to decrease withdrawal response associated with rocuronium

Purpose This randomized, double-blind, placebo-controlled study was conducted to examine the preventive effect of nafamostat mesilate, a kallikrein inhibitor, on the withdrawal response associated with rocuronium injection. Methods Ninety American Society of Anesthesiology (ASA) physical status I or II patients, aged 18–65 years, were randomly divided into two groups that received either a 1.5-ml solution containing 1.5 mg nafamostat mesilate diluted in a 5% glucose solution or a 1.5-ml 5% glucose solution. Anesthesia was induced by 5 mg/kg 2.5% thiopental. After confirming loss of consciousness, a tourniquet was applied to the mid forearm and tightened to block venous flow. The test solution was then administered, 1 min after which the tourniquet was removed and 0.6 mg/kg rocuronium was administered. Each patient’s response to rocuronium injection was graded on a four-point scale in a double-blind manner. Activated coagulation time and plasma potassium concentration were measured before and 5 and 10 min after nafamostat administration. Results The incidence of withdrawal response was 68.9% in the control group and 24.4% in the nafamostat group ( P