Phosphate binder pill burden, adherence, and serum phosphorus control among hemodialysis patients converting to sucroferric oxyhydroxide.

Background: Phosphate binders are widely used to achieve serum phosphorus control in patients with end-stage renal disease. However, the large pill burden associated with these medications may decrease adherence to therapy. In clinical trials, sucroferric oxyhydroxide (SO) demonstrated equivalent control of serum phosphorus to sevelamer, with a lower daily pill burden. We examined changes in phosphate binder pill burden, medication possession ratio (MPR), and phosphorus control among in-center hemodialysis (ICHD) patients converting to SO from another phosphate binder as part of routine care.

Materials and methods: Patients included in this retrospective analysis (N=490) were ≥18 years old, received ICHD at a large dialysis organization (LDO), and were enrolled in the LDO's pharmacy service. Patients converting to SO were those who had supply of another phosphate binder, received a first prescription fill for SO, and subsequently did not refill the non-SO phosphate binder. Patients were followed over the 6 months before and 6 months following the first SO fill and were censored from the analysis upon modality change, loss to follow-up, discontinuation of SO, or fill of a prescription for another phosphate binder after SO initiation (number censored=361). Outcome measures assessed were total phosphate binder pill burden and MPR, serum phosphorus, and percentage of patients with serum phosphorus ≤5.5 mg/dL.

Results: Among patients converting to SO, mean phosphate binder pill burden was 10.8 pills/day during baseline; this decreased to 5.5 pills/day during follow-up ( P <0.001). The percentage of patients with serum phosphorus ≤5.5 mg/dL increased from 22.0% to 30.0% ( P <0.001). Among patients not using the LDO pharmacy's automated refill management service (N=30), mean phosphate binder MPR increased from 0.68 during baseline to 0.80 during follow-up ( P =0.01).

Conclusion: In a cohort of ICHD patients, conversion to SO was associated with a reduction in pill burden, better adherence, and improvements in phosphorus control.