CYCLOSPORINE-A AND URSODEOXYCHOLIC ACID INTERACTION

Drug interactions with cyclosporine A(CsA) have frequently been reported. We used ursodeoxycholic acid (UDCA) as a symptomatic treatment for chronic active hepatitis C in a kidney transplanted patient with CsA monotherapy and we found such an interaction. After treatment with UDCA, gamma glutamyl transpeptidase (GGT), alkaline phosphatase (A. Ph) and alanine aminotransferase (ALAT) normalized and the patient felt well. Nevertheless, the CsA whole blood trough level increased from 150 ng/ml to 500 ng/ml. The daily dose was gradually decreased from 3.3 mg/kg to 1.76 mg/kg to obtain normal cyclosporinemia of about 150 ng/ml. This increase was mainly due to increased CsA absorption by improvement in cholestasis and by the direct effect of bile and bile salts on absorption of lipids and lipid soluble drugs.