Long-term low-dose spironolactone therapy is safe in oligoanuric hemodialysis patients

The Randomized Aldactone Evaluation Study showed that low-dose spironolactone treatment dramatically reduced mortality in patients with heart failure. However, the clinical use of this drug may be limited due to its tendency to cause life-threatening hyperkalemia in hemodialysis (HD) patients. We assessed whether low-dose spironolactone could be safely administered to HD patients for a long period. The study design comprised 2-month baseline and 6-month treatment periods. Sixty-one oligoanuric HD patients were administered a spironolactone dose of 25 mg/day. Serum potassium levels at baseline were compared with those during the treatment. Eleven patients discontinued the treatment because of adverse events other than hyperkalemia or for other reasons. The remaining 50 patients completed the trial, and none of them showed a potassium level of >6.8 mEq/l or required additional ion exchange resin therapy throughout the study period. The mean potassium levels during the treatment were higher than those at baseline; the differences were statistically significant, but only marginally. The safety of spironolactone should be examined in larger trials. However, from this study, we conclude that long-term low-dose spironolactone treatment is clinically safe for many HD patients. A more extensive treatment may help in determining whether spironolactone can reduce cardiovascular mortality in HD patients.