SAN DIEGO—Nearly 11% of hemodialysis (HD) patients who discontinued use of a phosphate binder did so because of side effects, according to study findings presented at Kidney Week 2012.

Using electronic medical records of Medicare patients receiving HD at a large dialysis organization, Thomas Alfieri, PhD, of DaVita Inc., in Denver, and colleagues analyzed phosphate binder prescriptions and the reasons for discontinuation (either switched or ceased taking a binder entirely). Two independent coders classified each reason for discontinuation into six categories and subsequently into 40 subcategories.

Of 30,933 reasons classified, 50.1% of records indicated that the patient discontinued the binder but contained no additional information. Another 27.4% cited “lab results” as a reason for discontinuation and 10.8% cited “patient-reported side effects.”

Furthermore, the analysis revealed that lanthanum carbonate use was associated with a disproportionately high rate of discontinuation. Although 14% of patients in the study were prescribed lanthanum carbonate, they accounted for 40% of the patient-reported side effects.

The investigators concluded that the high percentage of reported side effects resulting in binder discontinuation identifies an unmet need for improved phosphate binders. In addition, although a disproportionate number of patients prescribed lanthanum carbonate reported side effects, more work is needed to identify the relative tolerability of phosphate binders and potential explanations, such as prescription bias.