Recommended Dosage of Sevelamer for Hyperphosphatemia in CKD
The recommended starting dose of sevelamer for treating hyperphosphatemia in CKD patients is 800-1600 mg three times per day with meals, with dose adjustments based on serum phosphorus levels every two weeks to achieve target phosphorus levels. 1
Dosing Guidelines by CKD Stage
CKD Stages 3-4:
- Initiate phosphate binders when serum phosphorus exceeds 4.6 mg/dL despite dietary phosphorus restriction 2
- Target serum phosphorus range: 2.7-4.6 mg/dL 2
- Starting dose: 800 mg (one tablet) three times daily with meals 1
CKD Stage 5 (Dialysis):
- Initiate phosphate binders when serum phosphorus exceeds 5.5 mg/dL despite dietary phosphorus restriction 2
- Target serum phosphorus range: 3.5-5.5 mg/dL 2
- Starting dose: 800-1600 mg (1-2 tablets) three times daily with meals 1
- Typical effective dose: 7.1 ± 2.5 g/day (approximately 9 tablets of 800 mg daily) 3
Dose Titration Protocol
- Adjust dose by one tablet per meal in two-week intervals to achieve target serum phosphorus levels 1
- Monitor serum phosphorus monthly following initiation of therapy 2
- Maximum effective dose is individualized based on phosphorus control and tolerability 4
Special Considerations for Sevelamer Use
When to Choose Sevelamer Over Calcium-Based Binders:
- Preferred in dialysis patients with hypercalcemia (serum calcium >10.2 mg/dL) 2
- Preferred when PTH levels are <150 pg/mL on two consecutive measurements 2
- Preferred in patients with severe vascular or soft-tissue calcifications 2
- Consider in patients where calcium intake needs to be restricted 2
Combination Therapy:
- In dialysis patients with persistent hyperphosphatemia (>5.5 mg/dL) despite monotherapy, combine sevelamer with calcium-based binders 2
- When using combination therapy, ensure total elemental calcium intake (dietary + binders) does not exceed 2,000 mg/day 2
Monitoring Parameters
- Serum phosphorus: Target 3.5-5.5 mg/dL for CKD stage 5; 2.7-4.6 mg/dL for CKD stages 3-4 2
- Serum calcium: Maintain within normal range, preferably toward lower end (8.4-9.5 mg/dL) 2
- Calcium-phosphorus product: Maintain <55 mg²/dL² 2
- Monitor for gastrointestinal adverse effects (dyspepsia, constipation, diarrhea) 1
Common Pitfalls and Caveats
- Sevelamer should be taken with meals to effectively bind dietary phosphate 1
- Separate administration from other medications by at least 1 hour to avoid potential drug interactions, particularly with ciprofloxacin and mycophenolate mofetil 1
- Watch for gastrointestinal adverse effects, which are the most common reason for discontinuation 1
- Serious cases of dysphagia, bowel obstruction, and gastrointestinal ulceration have been reported, requiring careful monitoring especially in patients with gastrointestinal disorders 1
- Sevelamer has additional benefits beyond phosphate binding, including reduction in total and LDL cholesterol levels 4, 3
By following these dosing guidelines and monitoring parameters, sevelamer can effectively manage hyperphosphatemia in CKD patients while potentially offering additional cardiovascular benefits compared to calcium-based binders.