Sevelamer-Vista contains sevelamer, a non-absorbable, metal- and calcium-free phosphate-binding polymer. Sevelamer contains multiple amines separated by one carbon atom from the polymer backbone that attach a proton in the stomach. These amines, with the attached proton, bind negatively charged ions, such as phosphate from food, in the intestine. By binding phosphate in the gastrointestinal tract and reducing absorption, sevelamer reduces serum phosphate concentrations. Regular monitoring of serum phosphorus levels is necessary during treatment with phosphate-binding drugs.