Glutaphos is Contraindicated in CKD Patients with Hypophosphatemia
Do not use Glutaphos (sodium phosphate) in any patient with CKD and low serum phosphate—this represents a fundamental misunderstanding of the clinical scenario, as Glutaphos is a phosphate supplement indicated only for hypophosphatemia in patients with normal renal function, and is explicitly contraindicated in CKD patients with severely impaired renal function (less than 30% of normal). 1
Why Glutaphos is Contraindicated in CKD
Direct FDA Contraindication
- Glutaphos is absolutely contraindicated in patients with severely impaired renal function (less than 30% of normal), which encompasses most CKD patients, and is also contraindicated in the presence of hyperphosphatemia 1
- The product should be used with extreme caution in patients with renal function impairment or chronic renal disease, even in milder stages 1
The Clinical Context is Backwards
- CKD patients typically require phosphate restriction, not supplementation—the 2017 KDIGO guidelines focus entirely on lowering elevated phosphate levels toward the normal range in CKD G3a-G5D patients, not on treating hypophosphatemia 2
- Hypophosphatemia in a CKD patient is an unusual finding that warrants investigation for underlying causes such as malnutrition, aluminum toxicity, or adynamic bone disease, and bone biopsy may be reasonable in cases of unexplained hypophosphatemia 2
What to Do Instead: Investigate the Cause
Evaluate for Underlying Bone Disease
- Unexplained hypophosphatemia in CKD G3a-G5D is an indication for bone biopsy if knowledge of the type of renal osteodystrophy will impact treatment decisions 2
- Check PTH levels—persistently low PTH with hypophosphatemia may indicate adynamic bone disease, which is associated with increased cardiovascular calcification risk 2
Rule Out Aluminum Toxicity
- Measure serum aluminum levels, as aluminum intoxication can cause hypophosphatemia and osteomalacia in CKD patients 3
- The KDIGO guidelines recommend avoiding long-term use of aluminum-containing phosphate binders and dialysate aluminum contamination 2
Assess Nutritional Status
- Evaluate for protein-energy malnutrition, which can cause hypophosphatemia even in CKD patients 3
- Review medications that may bind phosphate inappropriately, such as excessive use of phosphate binders when not indicated 4, 5
Critical Pitfall to Avoid
The most dangerous error would be administering phosphate supplementation to a CKD patient without understanding the underlying cause of hypophosphatemia—this could precipitate hyperphosphatemia, worsen vascular calcification, and increase cardiovascular mortality risk, which is already the leading cause of death in CKD patients 2, 4