Failure to detect remarkable hypomagnesemia in renal transplant recipients receiving ciclosporin.

Serum magnesium as well as total and fractional urinary magnesium excretion were investigated in 87 renal transplant recipients under immunosuppression with azathioprine/prednisone (n = 18), ciclosporin/prednisone (n = 33) or ciclosporin/azathioprine/prednisone (n = 36). Only patients treated with ciclosporin and prednisone displayed significantly lower serum magnesium (1.8 +/- 0.03 mg/dl), compared to azathioprine-treated ones (2.0 +/- 0.07 mg/dl; p less than 0.05). Mean serum magnesium values of all three groups remained in the lower normal range (1.7-2.7 mg/dl). Fractional but not total magnesium excretion was significantly (p less than 0.05) higher in both ciclosporin-treated groups (5.8 +/- 0.38 and 5.6 +/- 0.40%) compared to patients on azathioprine (4.5 +/- 0.48%). None of the patients developed clinical signs of hypomagnesemia and only 7 patients were on oral supplementation with magnesium containing antacida. Our study did not confirm earlier observations of severe magnesium wasting and hypomagnesemia in renal transplant recipients under immunosuppression with ciclosporin.