Hyponatraemia and hyperkalaemia are more frequent in renal transplant recipients treated with tacrolimus than with cyclosporin. Further evidence for differences between cyclosporin and tacrolimus nephrotoxicities.

Background: This study was designed to examine the hypothesis that the nephrotoxicities caused by cyclosporin and tacrolimus might differ in respect of sodium and potassium handling.

Methods: 125 patients were studied retrospectively for the first 90 days after renal transplantation. Eighty were treated initially with cyclosporin and 45 with tacrolimus.