Randomized, double-blind, placebo-controlled trial of spironolactone for hypokalemia in continuous ambulatory peritoneal dialysis patients.

The incidence of hypokalemia in continuous ambulatory peritoneal dialysis (CAPD) patients is about 15-60%, leading to significant complications. There is no standard treatment other than potassium supplement in this setting. The aim of this study was to evaluate effect of spironolactone 25 mg/day in CAPD patients who have a history of hypokalemia. This is a randomized, double-blind, placebo-controlled, cross-over study in CAPD patients who had a history of hypokalemia. Study intervention is 4 weeks of oral spironolactone 25 mg/day or placebo, cross-over after a 2-week wash-out period. The primary outcome was the difference of serum potassium before and after 4 weeks of spironolactone treatment. Serum potassium was measured every 2 weeks, serum magnesium, urine and peritoneal fluid potassium measured before and after each treatment period. We enrolled 24 patients, and 20 completed the cross-over study. Ten patients were anuric. The total doses of potassium supplement were the same during the study period. Serum potassium levels before and after study intervention were not significantly different in both groups (4.23 ± 0.64 vs. 3.90 ± 0.59 mEq/L for spironolactone P = 0.077 and 3.84 ± 0.62 vs. 3.91 ± 0.52 for placebo P = 0.551). Total 24-h potassium, magnesium, sodium excretion, urine volume and ultrafiltration volume were not affected by spironolactone or placebo. There was one episode of hyperkalemia (5.6 mEq/L) during the spironolactone treatment period. Spironolactone 25 mg/day does not have a significant effect on serum potassium or urine and peritoneal excretion rate in CAPD patients who have a history of hypokalemia.