The phosphate binder equivalent dose

Area of Science:

• Nephrology
• Pharmacology
• Clinical Chemistry

Background:

• Phosphate binders are crucial for managing hyperphosphatemia in patients with chronic kidney disease.
• Various phosphate binders exist, including calcium salts, sevelamer, magnesium, lanthanum, and aluminum compounds.
• Comparing the efficacy of different binders is essential for effective patient management.

Purpose of the Study:

• To establish a standardized method for comparing the relative phosphate-binding capacity of different phosphate binders.
• To introduce the concept of the phosphate-binding equivalent dose (PBED) for quantitative assessment.
• To provide a framework for comparing binder prescriptions and for use in phosphate kinetic modeling.

Main Methods:

• Systematic review of in vivo human studies assessing phosphate binders.
• Measurement of phosphate recovery from stool and/or changes in urinary phosphate excretion.
• Calculation of the relative phosphate-binding coefficient (RPBC) for each binder, normalized to calcium carbonate (RPBC=1.0).

Main Results:

• Estimated RPBC values: lanthanum (2.0), anhydrous magnesium carbonate (1.7), aluminum carbonate (1.9), aluminum hydroxide (1.5), hydrated magnesium carbonate (1.3), sevelamer hydrochloride/carbonate (0.75), and calcium acetate (1.0).
• The phosphate-binding equivalent dose (PBED) is defined as binder dose (g) × RPBC.
• PBED allows for direct comparison of the phosphate-binding ability of different binders on a standardized scale.

Conclusions:

• The relative phosphate-binding coefficient (RPBC) provides a quantitative measure to compare diverse phosphate binders.
• The phosphate-binding equivalent dose (PBED) is a valuable tool for clinical decision-making and research.
• This standardized approach facilitates accurate comparisons of binder prescriptions and aids in phosphate kinetic modeling.