Troches for Hyperphosphatemia: A Case-Series Study by a Unique Administration Style of Chewable Tablets of Sucroferric Oxyhydroxide during Hemodialysis Sessions

Hyperphosphatemia is still one of critical issues in hemodialysis (HD) patients, phosphate binders, a main treatment to decrease serum phosphorus levels, also increases pill-burden to patients. To resolve this problem, we tried a troche (throat lozenges)-like administration style (troche therapy) of sucroferric oxyhydroxide (SFOH) during a HD session in a prospective case-series study. The patients were advised to keep chewable tablets containing 500 mg/tablet of SFOH in their oral cavities until the tablets were dissolving spontaneously, then to swallow their dissolved contents. According to patient tolerability, an administration dose was determined in each patient by an attending physician (one of co-authors). Six man and six woman with age of 62.1±22.4, resistant to routine therapies for hyperphosphatemia were enrolled with their informed consents. During one-year-observation period, three patients withdrew from the study due to drug-related causes, and four patients resigned the study due to drug-unrelated reasons. Other five patients continued the study over a year. Serum inorganic phosphorus (IP) levels were significantly reduced three months after starting SFOH (from 7.3±1.2 to 5.7±1.4 mg/dL, p. = 0.013, reduction rate 22.9±11.2%, p. = 0.009). Meanwhile, other phosphate binders were tapered in three patients and calcium carbonate was increased in one patient. Serum intact FGF23 levels were significantly reduced by 40.7±22.0% (p. = 0.042) and 47.8±25.7% (p. = 0.041) after three and four months, respectively. Log (intact FGF23) was well correlated with serum IP in total measured samples (r. = 0.762, p. < 0.0001, n. = 98). In conclusion, not only decrease serum phosphorus levels, but to reduce pill-burdens, the troche therapy of SFOH would be a possible and beneficial alternate to a conventional oral administration of PBs in some parts of hemodialysis patients.

Keywords: hyperphosphatemia, troche therapy, lozenges, pill-burden, polypharmacy, FGF23.