In a 4 month study, a group of 16 patients with stable renal graft function receiving triple immunosuppressive therapy including cyclosporin A (Cy A) were investigated for the levels of calcium. magnesium and zinc in erythrocytes. The patients were randomized to be converted to the new microemulsion formulation (Sandimmun Neoral@)ina I: I fashion (n=8) orto continue with the classical formulation (Sandimmun@)(n=8). The concentrations of creatinine, phosphate, alkaline phosphatase activity, calcium. magnesium and zinc were measured twice a month in blood plasma. The concentration of calcium.. magnesium and zinc in erythrocytes was also measured. The concentration of magnesium in blood plasma and erythrocytes during the study showed no deviation from normal values. The level of zinc in erythrocytes was almost twice as high as in normal healthy controls and was not dependent on Cy A formulation. Calcium content in erythrocytes of patients receiving Sandimmun@ was 27,6% higher than in healthy persons. Conversion of the patients to Sandimmun Neoral@ normalized the calcium concentration in erythrocytes and caused a transient increase of calcium levels in blood plasma.

Keywords: CyclosporinA, microemulsion formulation, renal transplantation, erythrocyte, Magnesium, Zinc