Reasons for phosphate binder discontinuation vary by binder type

Nonadherence to phosphate binder regimen is common among end-stage renal disease patients and contributes to elevated phosphorus levels. Pill burden, side effects, complex regimens, and cost all contribute to nonadherence. We retrospectively analyzed reasons for discontinuation in hemodialysis patients receiving treatment at a large U.S. dialysis organization to better understand the drivers of nonadherence for particular phosphate binders.

Patient electronic medical records were reviewed to identify phosphate binder prescriptions and reasons for discontinuation. Reasons for discontinuation were categorized and the percentage of patients on each type of phosphate binder was calculated within categories.

Medicare patients of age ≥18 years, receiving in-center hemodialysis treatment between July 1, 2009, and June 30, 2011, were included in the analysis.

We classified 30,933 patient records with a stated reason for phosphate binder discontinuation for this study. Of these records, 50.1% cited that the patient discontinued the phosphate binder but contained no additional information; "lab results" were cited for 27.4% of the reasons for discontinuation and "patient-reported side effects" for 10.8%. Although patients on lanthanum carbonate accounted for 14% of the total number reasons for discontinuation assessed, they comprised 40% of the "patient-reported side effects" category and were similarly overrepresented in 4 of the 5 subcategories.

The high percentage of patient-reported side effects resulting in discontinuation identifies an unmet need for improved phosphate binders. A disproportionate percentage of patients prescribed lanthanum carbonate reported side effects, however further work is needed to identify the relative tolerability of phosphate binders and potential explanations.