Isolated hyperkalemia associated with cyclosporine administration in allogeneic stem cell transplantation for renal cell carcinoma.

Two patients with advanced renal cell carcinoma underwent allogeneic hematopoietic stem cell transplantation and received cyclosporine (CSP) as part of their immunosuppressive therapy. Despite adequate renal function, both patients developed hyperkalemia. CSP was the only pharmaceutical agent to which this electrolyte abnormality could be attributed. Evaluation of renal tubule function suggested that CSP-associated isolated hyperkalemia resulted from tubular resistance to aldosterone. We propose that the presence of a single functional kidney may be a risk factor for isolated hyperkalemia due to CSP.