Effect of Phosphate Binders on Supplemental Iron Absorption in Healthy Subjects

Abstract

A single-dose, prospective, randomized, four-treatment, four-period crossover study was conducted to determine the acute effect of therapeutically equivalent doses of three commonly used phosphate binders on oral iron absorption. Twenty-three healthy subjects received 65 mg of elemental iron alone and with each phosphate binder (calcium carbonate 3000 mg, calcium acetate 2668 mg, or sevelamer HCl 2821 mg). Area under the change in plasma iron concentration-time curve over 6 hours postdosing was measured. ANOVA was used to assess the statistical significance of differences in iron absorption among the treatments. The relative bioavailability of iron administered with each phosphate binder compared to iron administered alone was estimated. The relative iron bioavailabilities (95% confidence intervals) for the calcium carbonate, calcium acetate, and sevelamer HCI treatments were 0.81 (0.70, 0.94), 0.73 (0.63, 0.85), and 0.90 (0.78, 1.05), respectively. Thus, single doses of both calcium-based phosphate binders significantly reduced single-dose iron absorption, while sevelamer HCl did not.

Iron deficiency in children with early chronic kidney disease

“…Medications frequently used in CKD such as bicarbonate, antacids and calcium-based phosphorus binders decrease iron absorption [13]. Almost 60% of our iron-deficient patients were on at least one of these medications, suggesting that this may be a factor contributing to iron deficiency.…”

Effects of Epigallocatechin Gallate, L-Ascorbic Acid, α-Tocopherol, and Dihydrolipoic Acid on the Formation of Deoxyguanosine Adducts Derived From Lipid Peroxidation

“…We used 25 μM FeSO 4 in our reactions to mimic the concentrations in human plasma (34,35). We did not use H 2 O 2 because studies in cells enriched with DHA showed that iron-oxygen complexes are more potent than H 2 O 2 in initiating free radical-mediated oxidation (36).…”

Phosphate binders in patients with chronic kidney disease

“…For calcium-based binders and sevelamer, the dose can be increased to a maximum of six or more tablets daily. Other medicines should be given separately as phosphate binders can interfere with the absorption of drugs such as oral iron 13 and ciprofloxacin. 14 …”