[Case of hyperkalemia possibly caused by gabexate mesilate]

We report a case of hyperkalemia in a recipient of living-related liver transplantation. The patient received a continuous infusion of gabexate mesilate at 60 mg x hr(-1) starting about 1 hr after the induction of anesthesia. The serum potassium concentration (K+) was increased from 4.53 mEq x l-(1) to 5.08 mEq x l(-1) within about 1 hr. Thereafter, a massive blood loss caused by an accidental damage of the portal vein necessitated rapid fluid therapy to maintain blood pressure. We observed an abnormal ECG recording including a wide QRS complex and a high T wave when about 30 units of leukocytes-reduced red cell concentrates had been transfused. Blood gas analysis showed high K+ (7.52 mEq x l(-1)) and metabolic acidosis (pH 7.167, base excess-12.5 mmol x l(-1)). We successfully controlled K+ with combination of therapies before causing any cardiac events to the patient. Gabexate mesilate is one possible cause of hyperkalemia in the present case because an increase in K+ was observed before transfusion, and transfusion might have augmented the effect. Gabexate mesilate is one of the protease inhibitors. Naphamostat mesilate, another protease inhibitor, is known to cause hyperkalemia by limiting potassium excretion from the kidney through an inhibition of Na/K-ATPase at the cortical collecting ducts. Although the mechanism by which gabexate mesilate causes hyperkalemia is unclear, it would be of benefit to use this drug cautiously, as it may cause hyperkalemia.