Abstract
It is necessary to carefully monitor the administration of Cyclosporine (CyA) because it has a narrow therapeutic range and its pharmacokinetics are affected by a variety of factors. Here we report a case in which the CyA concentration in whole blood was elevated accompanying deterioration in renal function. The patientwas a 54-year-old woman who had undergone bone marrow transplantation. She was given CyA (3.0mg/kg/day) and fluconazole (FLCZ, 100mg/day), intravenously and the CyA concentration was steady at the beginning. However, the serum creatinine level began to gradually increase on the 12th day following transplantation and an increase in CyA concentration was observed on the 19th day. Renal function continued deteriorating, and there was a 44% decrease in CyA clearance as compared with the time that it was steady. These results imply that the decrease in the clearance of CyA, a hepatic excretion drug, was due to renal dysfunction. Further testing revealed that the serum FLCZ concentration was elevated in conjunction with the decrease in CyA clearance. Taken together, these results suggest that the large reduction in CyA clearance was due to interaction with FLCZ, a renal excretion drug, as well as the renal dysfunction. It is therefore necessary to closely monitor the CyA concentration in such a patient.
