Cyclosporine nephrotoxicity and early posttransplant hyperkalemia in living-donor renal recipients: report of 4 cases.

OBJECTIVES Hyperkalemia is an electrolyte disorder that may occur during the first few months after a renal transplant, in patients undergoing cyclosporine immunosuppression. We present our experience with cyclosporine-associated hyperkalemia in living-donor renal transplant recipients, with isolated clinically relevant hyperkalemia soon after surgery. MATERIALS AND METHODS We report 4 living-donor renal recipients with hyperkalemia soon after transplant. RESULTS Severe unexpected hyperkalemia (7.5- 9.4 mmol/L) was noted in our patients 12, 20, 22, and 34 days after transplant. The C2 cyclosporine concentration was within recommended range or slightly greater than 1200 ng/mL. The hypertonic glucose/insulin treatment along with potassium diet was without results. A reduction in daily cyclosporine dosages, along with 1- to 2-week administration of fludrocortisone was effective. The patients became normokalemic taking a standard, triple-drug immunosuppression protocol, and were discharged home with normal renal function. There were no repeat episodes of hyperkalemia in any of the patients during 12 months of follow-up. CONCLUSIONS Cyclosporine should be considered a cause of hyperkalemia in renal transplant recipients. Successful treatment with fludrocortisone confirms that transitional pseudohypoaldosteronism has a potential nephrotoxic effect of cyclosporine. We recommend close monitoring of the cyclosporine concentration and administering fludrocortisone when treating hyperkalemia in renal transplant recipients.