Cyclosporine pharmacokinetics in nephrotic and kidney-transplanted children

The pharmacokinetic parameters of cyclosporine (CsA) were determined in 23 kidney transplant recipients and 19 children with nephrotic syndrome, after intravenous and oral administration. The mean bioavailability was 39%, blood clearance was 0.55 l.h-1.kg-1 and volume of distribution at steady-state was 2.77 l.kg-1. The absorption profile was monophasic (67%), biphasic (29%) or poor (4%). The maximum blood concentration of CsA was significantly higher in children with a monophasic profile than in children with a biphasic profile (550 vs 380 ng.ml-1). Blood clearance was significantly higher in the transplant recipients than in the patients with nephrotic syndrome (0.65 vs 0.43 l.h-1.kg-1. Although age, haematocrit, creatinine clearance, serum albumin and cholesterol differed between the two groups, only haematocrit and creatinine clearance were significantly (negatively) correlated with CsA clearance.