What phosphate binders can be used to manage hyperphosphatemia?

Phosphate Binders for Managing Hyperphosphatemia

Both calcium-based phosphate binders and non-calcium-based phosphate binders (such as sevelamer) are effective in lowering serum phosphorus levels and can be used to manage hyperphosphatemia in patients with chronic kidney disease. 1

Types of Available Phosphate Binders

• Calcium-based binders: Calcium acetate and calcium carbonate are effective, widely used, and relatively inexpensive options for lowering serum phosphorus 1
• Sevelamer (hydrochloride or carbonate): A non-calcium, non-aluminum phosphate binder that effectively reduces serum phosphorus without increasing calcium levels 1, 2
• Lanthanum carbonate: A non-calcium-based binder with high phosphate binding capacity 1, 3
• Sucroferric oxyhydroxide (Velphoro): An iron-based phosphate binder that has proven as effective as sevelamer with a lower pill burden 3
• Aluminum-based binders: May be used only as short-term therapy (maximum 4 weeks) in patients with severe hyperphosphatemia (>7.0 mg/dL) due to toxicity concerns 1
• Magnesium salts: Can be used as phosphate binders, though they have potential for systemic accumulation 4

Selection Criteria for Phosphate Binders

First-Line Options:

• For most patients: Calcium-based phosphate binders (calcium acetate or calcium carbonate) are reasonable initial choices due to effectiveness and lower cost 1, 4
• Dosing considerations: The total dose of elemental calcium from calcium-based binders should not exceed 1,500 mg/day, and total calcium intake (dietary plus binders) should not exceed 2,000 mg/day 1

When to Use Non-Calcium Binders:

• Hypercalcemia: Avoid calcium-based binders in patients with corrected serum calcium >10.2 mg/dL 1
• Suppressed PTH: Avoid calcium-based binders when plasma PTH levels are <150 pg/mL on two consecutive measurements 1
• Vascular calcification: Non-calcium containing phosphate binders are preferred in patients with severe vascular or other soft-tissue calcifications 1
• Coronary artery calcification: Sevelamer has been shown to prevent progression of coronary artery and aortic calcification compared to calcium-based binders 1

Combination Therapy:

• For dialysis patients who remain hyperphosphatemic (serum phosphorus >5.5 mg/dL) despite monotherapy, a combination of calcium-based and non-calcium-based binders should be used 1

Special Considerations

• Calciphylaxis: In patients with calciphylaxis, limit exposure to excess calcium and phosphate; non-calcium containing binders are preferred 5
• Pediatric patients: Sevelamer has proven efficacy and safety in children with CKD, particularly when hypercalcemia is a concern 1
• Cost considerations: Calcium-based binders are considerably less expensive than non-calcium alternatives, which may influence selection when cost is a factor 4, 6
• Pill burden: Sucroferric oxyhydroxide may be preferred when pill burden is a concern, as it has shown similar efficacy to sevelamer with fewer pills 3

Monitoring and Follow-up

• Monitor serum phosphorus levels monthly following initiation of phosphate binder therapy 1
• Regularly assess serum calcium levels to detect hypercalcemia, especially with calcium-based binders 1
• Monitor PTH levels to avoid oversuppression when using calcium-based binders 1
• Assess for signs of vascular calcification, particularly in patients on long-term calcium-based binder therapy 1

Cautions and Pitfalls

• Avoid initiating phosphate binders in patients with normal phosphate levels, as this may not be beneficial and could potentially be harmful 1
• Be aware that calcium-based binders may contribute to hypercalcemia, vascular calcification, and PTH suppression 1, 4
• Aluminum-based binders should only be used short-term (≤4 weeks) due to risk of toxicity 1
• Recognize that gastrointestinal side effects are common with resin-based binders like sevelamer 7
• Consider that lanthanum carbonate has potential for tissue accumulation, though clinical significance remains uncertain 4, 7