A randomized controlled trial of fludrocortisone for the treatment of hyperkalemia in hemodialysis patients.
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.


CONCLUSIONS
Administering fludrocortisone to hyperkalemic hemodialysis patients is safe and well tolerated, but does not achieve clinically important decreases in serum potassium levels.
Kaisar
Mohammed O
MO
Department of Renal Medicine, University of Queensland, Princess Alexandra Hospital, Brisbane, QLD, Australia.
Wiggins
Kathryn J
KJ
Sturtevant
Joanne M
JM
Hawley
Carmel M
CM
Campbell
Scott B
SB
Isbel
Nicole M
NM
Mudge
David W
DW
Bofinger
Andrew
A
Petrie
James J B
JJ
Johnson
David W
DW
D000284:Administration, Oral; D005260:Female; D005438:Fludrocortisone / Q000008:administration & dosage*; D006801:Humans; D006947:Hyperkalemia / Q000097:blood* / Q000150:complications / Q000188:drug therapy*; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000150:complications / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000097:blood*; D011446:Prospective Studies; D006435:Renal Dialysis
D011188:Potassium; D005438:Fludrocortisone