Urinary excretion of ciclosporin and 17 of its metabolites in renal allograft recipients

Renal elimination of the immunosuppressant ciclosporin is virtually unknown. Therefore, in 17 renal allograft recipients under steady-state conditions we studied the urinary excretion of ciclosporin and 17 of its metabolites in blood and 24-hour urine. Patients with liver dysfunction or treated with drugs potentially influencing the metabolism and elimination of ciclosporin were excluded from the study. Ciclosporin and its metabolites were measured by HPLC. Metabolite but not ciclosporin excretion was strongly correlated with creatinine clearance. Metabolites 18 and 26 (beta, epsilon-cyclic metabolite) were rarely found in blood but were excreted in considerable amounts in urine. Approximately 3% of the administered dose of ciclosporin per day undergoes renal elimination in unchanged form or as metabolites investigated. The data suggest glomerular filtration of ciclosporin metabolites, a difference in the rate of elimination between ciclosporin and the metabolites and some kind of metabolism or active transport mechanism for metabolites in the kidney

Ciclosporin metabolite pattern in blood and urine of kidney graft patients in relation to liver function

Ciclosporin, an immunosuppressant, is metabolized by the liver cytochrome P450 system. Changes in the pattern of its metabolites in blood and urine in patients with disturbed liver function have been studied. Forty seven kidney graft patients receiving 2.9 mg/kg/d ciclosporin b.i.d., and no additional medication that would interfere with ciclosporin metabolism, were allocated to three groups according to liver function: I with normal liver function (n = 19), II with elevated liver enzyme activity or bilirubin concentration in serum (n = 20), and III with cholestasis (n = 8). Ciclosporin and 17 metabolites were determined in blood and 24 h-urine. In blood the trough concentrations of metabolites M19 and M1A were significantly higher in group III than in groups I and II. The total quantity of metabolites excreted in 24 h-urine was significantly different for H230, M4N69 and M1A (group III greater than I = II). Renal excretion of the daily dose of ciclosporin in patients in group I was 2.7%, group II 3% and group III 5.7%. In group III compared to group I the ciclosporin metabolite pattern was shifted to a relatively higher concentration of M19 in blood and of H 230, M19 and M1A in urine. Since high ciclosporin metabolite concentrations appear to be associated with nephrotoxicity, the metabolite pattern in patients with impaired liver function should be monitored

Diltiazem increases blood concentrations of cyclized cyclosporine metabolites resulting in different cyclosporine metabolite patterns in stable male and female renal allograft recipients

1Six male and six female stable renal allograft recipients under cyclosporine immunosuppression and without concomitant therapy with drugs known either to induce or inhibit CYP3A enzymes were included in the study and received 180 mg day−1 diltiazem for 1 week in a two-period cross-over fashion. Cyclosporine (352±56 mg day−1) was given in two daily oral doses. The daily doses were not changed during the study. Blood samples were collected for 12 h after receiving cyclosporine alone and after receiving diltiazem in addition for 1 week. Cyclosporine and nine of its metabolites were quantified using h.p.l.c