The prescription of a higher number of phosphate binder pills is associated with lower medication adherence and worse serum phosphorus control

Abstract

【Objectives】 To examine the influence of the prescribed phosphate binder pill burden on medication adherence and serum phosphorus levels in Japanese hemodialysis patients. 【Methods】Adherence to phosphate binders was assessed using a questionnaire in 229 chronic hemodialysis patients that were being treated with phosphate binders. We analyzed the relationships between the number of monthly prescribed phosphate binder pills and adherence according to the questionnaire or other patient characteristics including the serum calcium, phosphorus, or intact parathyroid hormone level. 【Results】The median monthly pill burden was 210 pills, and 50% of the patients were receiving monotherapy. The higher pill burden group exhibited a younger age, a longer hemodialysis vintage, and higher serum phosphorus levels. A positive linear relationship was also observed between the number of phosphate binder pills and the serum phosphorus level. Approximately 30-40% of the patients were non-adherent. The patients that forgot to take the pills, had pills remaining, or wanted to reduce the number of pills they were taking exhibited a higher pill burden and higher serum phosphorus levels. In addition, the proportions of patients that had pills remaining or felt that they were taking many/too many pills rose as the number of prescribed pills increased. Furthermore, more non-adherent patients felt that they were taking many/too many pills compared with the adherent patients. 【Conclusion】The prescription of a higher number of phosphate binder pills is associated with lower medication adherence and worse serum phosphorus control.