Adherence rates to ferric citrate as compared to active control in patients with end stage kidney disease on dialysis.
Oral phosphate binders are the main stay of treatment of hyperphosphatemia. Adherence rates to ferric citrate, a recently approved phosphate binder, are unknown.



We conducted a post-hoc analysis to evaluate whether adherence rates were different for ferric citrate vs. active control in 412 subjects with end stage kidney disease (ESKD) who were randomized to ferric citrate vs. active control (sevelamer carbonate and/or calcium acetate). Adherence was defined as percent of actual number of pills taken to total number of pills prescribed.



There were no significant differences in baseline characteristics including gender, race/ethnicity, and age between the ferric citrate and active control groups. Baseline phosphorus, calcium, and parathyroid hormone levels were similar. Mean (SD) adherence was 81.4% (17.4) and 81.7% (15.9) in the ferric citrate and active control groups, respectively (P = 0.88). Adherence remained similar between both groups after adjusting for gender, race/ethnicity, age, cardiovascular disease (CVD), and diabetic nephropathy (mean [95% CI]: 81.4% [78.2, 84.6] and 81.5% [77.7, 85.2] for ferric citrate and active control, respectively). Gender, race/ethnicity, age, and diagnosis of diabetic nephropathy did not influence adherence to the prescribed phosphate binder. Subjects with CVD had lower adherence rates to phosphate binder; this was significant only in the active control group.



Adherence rates to the phosphate binder, ferric citrate, were similar to adherence rates to active control. Similar adherence rates to ferric citrate are notable since tolerance to active control was an entry criteria and the study was open label. Gender, race/ethnicity, nor age influenced adherence.
University of Colorado, Aurora, Colorado, USA.
Diana
D
Jalal
University of Utah, Salt Lake, Utah, USA.
Molly
M
McFadden
Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
Jamie P
JP
Dwyer
Henry Ford Hospital, Detroit, Michigan, USA.
Kausik
K
Umanath
Louisiana State University Health Center, New Orleans, Louisiana, USA.
Erwin
E
Aguilar
Ben-Gurion University of the Negev, Beer Sheba and Barzilai University Medical Center, Ashkelon, Israel.
Yoram
Y
Yagil
Baystate Medical Center, Springfield, Massachusetts, USA.
Barbara
B
Greco
Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
Mohammed
M
Sika
Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
Julia B
JB
Lewis
University of Utah, Salt Lake, Utah, USA.
Tom
T
Greene
University of Pennsylvania, Philadelphia, Pennsylvania, USA.
Simin
S
Goral
D002614:Chelating Agents / Q000627:therapeutic use*; D005260:Female; D005290:Ferric Compounds / Q000378:metabolism / Q000627:therapeutic use*; D006801:Humans; D007676:Kidney Failure, Chronic / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis / Q000379:methods*
D002614:Chelating Agents; D005290:Ferric Compounds; C025314:ferric citrate
Hyperphosphatemia; adherence; ferric citrate; phosphate binder