Mineralocorticoid therapy lowers serum potassium in patients with end-stage renal disease

Hyperkalemia is a commonly encountered problem in dialysis patients with end-stage renal disease. In this study we evaluated the effect of mineralocorticoid therapy (MCT; fludrocortisone 0.1-0.3 mg per os daily) on serum potassium of hyperkalemic end-stage renal disease patients. Consecutive monthly clinical and biochemical profiles 3-6 months before and after MCT were compared. Twenty-one patients with a mean age (± SE) of 54 ± 4 years (11 male and 10 female) were studied. Two patients were dropped from this study because they required a change in prescription of dialysis after starting MCT. Mean serum potassium levels significantly fell (p < 0.001) during the post- MCT period (4.9 ± 0.1 mEq/1) compared with potassium levels during the pre-MCT (5.6 ± 0.1 mEq/1) period. All patients except 1 showed a reduction in serum potassium levels after MCT. Pre- and post-MCT values were not different for body weight, mean blood pressure, blood urea nitrogen, serum glutamic-oxaloacetic transaminase, lactate dehydrogenase, sodium, chloride, bicarbonate, creatinine and albumin. Since the majority of the patients were anuric (n = 15), a decrease in serum potassium values in the post-MCT period was not due to loss of potassium in the urine. MCT appears to decrease serum potassium values in patients with end-stage renal disease by extrarenal mechanisms. We conclude that MCT can be used safely to lower serum potassium in patients with end-stage renal disease.