EFFECTS OF DIFFERENT ROUTES OF CYCLOSPORINE-A ADMINISTRATION ON BLOOD-LEVELS IN PATIENTS UNDERGOING BONE-MARROW TRANSPLANTATION

This follow-up study has been carried out on 15 bone marrow transplant recipients treated intravenously with cyclosporin A (CsA) as a bolus (1.25-2.5 mg/kg/12 h) or by continuous infusion (1-3 mg/kg/24 h) from -2 until the 21st day after transplantation. All patients were subsequ ently treated with CsA orally at a starting dose of 6.25 mg/kg/12 h; t his starting dose was then adjusted on the basis of CsA blood levels u ntil the 60th day after transplantation, followed by progressive reduc tion and withdrawal within 6-12 months. In whole blood, trough levels of polyclonal (P) and monoclonal (M) CsA were monitored by a FPIA meth od and the polyclonal/monoclonal ratio (P/M) was calculated, This rati o was lower during CsA administration as a bolus or by continuous infu sion than during oral administration; the decrease was statistically s ignificant. This difference was probably due to first-pass metabolism which occurs in the liver and gut after oral administration.