Original Investigation
Dialysis Therapy
A Randomized Controlled Trial of Fludrocortisone for the Treatment of Hyperkalemia in Hemodialysis Patients

https://doi.org/10.1053/j.ajkd.2006.01.014Get rights and content

Background: Previous small uncontrolled studies suggested that fludrocortisone may significantly decrease serum potassium concentrations in hemodialysis patients, possibly through enhancement of colonic potassium secretion. The aim of this study is to evaluate the effect of oral fludrocortisone on serum potassium concentrations in hyperkalemic hemodialysis patients in an open-label randomized controlled trial. Methods: Thirty-seven hemodialysis patients with predialysis hyperkalemia were randomly allocated to administration of either oral fludrocortisone (0.1 mg/d; n = 18) or no treatment (control; n = 19) for 3 months. The primary outcome measure was midweek predialysis serum potassium concentration, which was measured monthly during the trial. Prospective power calculations indicated that the study had an 80% probability of detecting a decrease in serum potassium levels of 0.7 mEq/L (0.7 mmol/L). Results: Baseline patient characteristics were similar, except for slightly longer total weekly dialysis hours in the fludrocortisone group (13.0 ± 1.3 versus 12.1 ± 1.0; P = 0.02). At the end of the study period, no significant changes in serum potassium concentrations were observed between the fludrocortisone and control groups (4.8 ± 0.5 versus 5.2 ± 0.7 mEq/L [mmol/L], respectively; P = 0.10). Similar results were obtained when changes in serum potassium levels over time were examined between the 2 arms by using repeated-measures analysis of variance, with or without adjustment for total weekly dialysis hours. Secondary outcomes, including predialysis mean arterial pressure, interdialytic weight gain, serum sodium level, and hospitalization for hyperkalemia, were not significantly different between groups. There were no observed adverse events. Conclusion: Administering fludrocortisone to hyperkalemic hemodialysis patients is safe and well tolerated, but does not achieve clinically important decreases in serum potassium levels.

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Study Subjects

All adult patients receiving in-center hemodialysis at the Princess Alexandra Hospital (Brisbane, Australia) or Logan Hospital (Logan City, Australia) were invited to participate in the study if they met the following inclusion criteria: (1) 18 years or older, (2) midweek predialysis potassium concentration greater than 4.5 mEq/L (>4.5 mmol/L; the upper reference limit for the laboratory) and less than 7.0 mEq/L (<7.0 mmol/L) during the 3 months before study commencement, and (3) able to give

Results

Numbers of patients who entered the study, were assigned to a study group, and completed the protocol are shown in Fig 1. Thirty-seven of 41 patients who entered the study completed the study protocol and were included in the intention-to-treat analysis (18 patients, fludrocortisone group; 19 patients, control group). Baseline demographics of the 2 groups were similar, except for longer dialysis hours in the fludrocortisone cohort (Table 1).

At the end of the 3-month study period, midweek

Discussion

Results of the present study show that administering fludrocortisone to hyperkalemic hemodialysis patients is safe and well tolerated, but does not achieve decreases in serum potassium levels that are either statistically significant or clinically important. To our knowledge, this is the only randomized controlled trial of fludrocortisone administration for the treatment of hyperkalemia in hemodialysis patients.

Results of this study differ from those of 3 previous uncontrolled studies, which

Acknowledgment

The authors thank the nursing staff of the Princess Alexandra Hospital Haemodialysis Unit for their invaluable assistance.

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Originally published online as doi:10.1053/j.ajkd.2006.01.014 on March 17, 2006.

Support: None. Potential conflicts of interest: None.

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