The Effect of Tailoring Phosphate Binder Doses on Serum Phosphorus Levels in Adult Chronic Hemodialysis Patients

Compliance with phosphate binder (PB) in hemodialysis patients usually is poor. The purpose of this study was to assess the effect of altering the pattern of PB ingestion to coincide with dietary intake of phosphorus (P) with repeated individual instruction regarding the method and importance of taking the PB. Patient compliance was determined by monitoring serum P levels. Seventeen adult chronic hemodialysis patients were studied for 4 months (group 1) along with an age- and sex-matched control group (group 2). Data included biochemical parameters, protein catabolic rate (PCR), reported dietary protein intake (DPI), and P. Each subject was instructed to continue taking the prescribed amount of PB, but to adjust the times it was taken according to his or her eating pattern. The instructions were reinforced weekly for 2 months during regular dialysis treatments. At baseline, PCR in group 1 was significantly higher than in group 2 (67.81 ± 16.31 v 56.94 ± 13.06; P < 0.05). At the end of the study, all parameters in group 2 were essentially unchanged. Group 1 showed a slight decrease in serum P levels (1.68 ± 0.48 mmol/L [5.19 ± 1.49 mg/dL] to 1.60 ± 0.49 mmol/L [4.94 ± 1.52 mg/dL) in the face of increased DPI evidenced by a significant increase in PCR (56.94 ± 13.06 to 65.12 ± 15.96; P < 0.01). An increase in DPI is accompanied by an increase in dietary P intake due to the high P content of protein-containing foods. Since serum P levels decreased while DPI increased, compliance with PB therapy was improved. This type of intense individual instruction may be applicable to other aspects of patient care such as medications and diet.