Why is the patient on Sevelamer (phosphate binder)?

Sevelamer Use in Chronic Kidney Disease

Sevelamer is prescribed for the control of serum phosphorus in patients with chronic kidney disease (CKD) on dialysis who have hyperphosphatemia, particularly those with hypercalcemia, low PTH levels, vascular calcifications, or high cardiovascular risk profiles. 1, 2

Indications for Sevelamer

Sevelamer is specifically indicated for patients with:

• Hyperphosphatemia (serum phosphorus >5.5 mg/dL) in CKD patients on dialysis 2
• Hypercalcemia (corrected serum calcium >10.2 mg/dL) 1
• Low parathyroid hormone levels (<150 pg/mL) 1
• Evidence of vascular or soft tissue calcifications 1
• High cardiovascular risk profile 1
• Patients exceeding 2,000 mg total elemental calcium intake from calcium-containing phosphate binders 3

Advantages of Sevelamer Over Calcium-Based Binders

Sevelamer offers several important benefits:

• Reduced mortality risk: Sevelamer reduces all-cause mortality compared to calcium-based binders (odds ratio of 0.39) 1
• Prevention of vascular calcification: Sevelamer significantly reduces the progression of aortic and coronary artery calcification compared to calcium-based phosphate binders 3, 1
• Fewer hypercalcemic episodes: Patients experience less hypercalcemia and less suppression of PTH 3, 1
• Lipid-lowering effects: Sevelamer reduces blood levels of cholesterol and LDL, providing additional cardiovascular protection 3, 4

Dosing and Administration

• Starting dose: 800-1600 mg with each meal (1-2 tablets of 800 mg or 2-4 tablets of 400 mg) 2
• Dose titration: Adjust by one tablet per meal at two-week intervals based on serum phosphorus levels 2
• Target phosphorus levels:
  • CKD Stage 3-4: 2.7-4.6 mg/dL
  • CKD Stage 5 (dialysis): 3.5-5.5 mg/dL 1
• Administration: Must be taken with meals to effectively bind dietary phosphate 1, 2

Monitoring Parameters

Monthly monitoring is recommended for:

• Serum phosphorus
• Serum calcium
• Calcium-phosphorus product (target <55 mg²/dL²)
• PTH levels 1

Clinical Considerations and Cautions

• Gastrointestinal effects: Sevelamer may cause constipation, nausea, and vomiting 2
• Drug interactions: Other medications should be administered at least 1 hour before or 3 hours after sevelamer to minimize potential interactions 1
• Contraindications: Bowel obstruction, dysphagia, severe GI motility disorders, or known hypersensitivity to sevelamer 2
• Enteral feeding: While not FDA-approved for crushing, evidence suggests sevelamer tablets may be crushed for enteral feeding tube administration with proper preparation 5

Practical Approach to Patient Selection

1. First-line: Consider calcium-based phosphate binders for patients with normal serum calcium, PTH >150 pg/mL, no vascular calcification, and normal cardiovascular risk
2. Switch to sevelamer: When patients develop hypercalcemia, have low PTH, show evidence of vascular calcification, or have high cardiovascular risk
3. Combination therapy: For patients remaining hyperphosphatemic on monotherapy, consider combining calcium-based and non-calcium binders, ensuring total elemental calcium intake does not exceed 2,000 mg/day 3, 1

Sevelamer's ability to control phosphorus levels while reducing cardiovascular calcification and mortality makes it an essential medication for many CKD patients on dialysis with hyperphosphatemia, particularly those at high risk for cardiovascular complications.