Management of Alkaline Phosphatase of 137
I need to clarify: An alkaline phosphatase (ALP) of 137 U/L is not hyperphosphatemia—this is a completely different laboratory value. Alkaline phosphatase is an enzyme marker, while serum phosphorus (phosphate) is measured in mg/dL. Your question appears to contain a critical error in terminology.
If You Meant Serum Phosphorus of 13.7 mg/dL (Severe Hyperphosphatemia)
For severe hyperphosphatemia >7.0 mg/dL, hemodialysis is the definitive treatment to rapidly lower phosphorus, and you should arrange this urgently. 1
Immediate Management Steps:
- Initiate emergency hemodialysis for phosphorus >7.0 mg/dL, particularly if symptomatic hypocalcemia is present 1, 2
- Aluminum-based phosphate binders may be used for short-term therapy (maximum 4 weeks, one course only) while arranging dialysis 3, 1
- Assess renal function immediately—severe hyperphosphatemia of this magnitude indicates either acute kidney injury, chronic kidney disease stage 5, or a massive phosphate load 4
After Acute Stabilization:
- Restrict dietary phosphorus to 800-1,000 mg/day while maintaining adequate protein intake 3, 5, 1
- Initiate non-calcium-based phosphate binders (sevelamer, lanthanum carbonate, or sucroferric oxyhydroxide) as first-line therapy 5, 1
- Avoid calcium-based binders if corrected serum calcium >10.2 mg/dL, PTH <150 pg/mL, or severe vascular calcifications are present 3, 1, 2
- Monitor serum phosphorus, calcium, and PTH monthly after treatment initiation 3, 5
If You Meant Alkaline Phosphatase of 137 U/L (Mildly Elevated)
An ALP of 137 U/L (assuming normal range ~30-120 U/L) is only mildly elevated and requires investigation of the underlying cause rather than treatment of the number itself:
Differential Diagnosis to Investigate:
- Bone disease: Paget's disease, osteomalacia, bone metastases, healing fractures
- Liver disease: Cholestasis, biliary obstruction, hepatitis, cirrhosis
- CKD-mineral bone disorder: Secondary hyperparathyroidism with high bone turnover 3
- Physiologic: Pregnancy, adolescent growth spurt
Diagnostic Approach:
- Fractionate ALP into bone-specific and liver-specific isoenzymes if the source is unclear
- Check GGT (gamma-glutamyl transferase)—if elevated, suggests hepatobiliary source
- Obtain liver function tests, serum calcium, phosphorus, PTH, and vitamin D levels
- Consider imaging (ultrasound for liver/biliary tree, bone scan if bone disease suspected)
The management depends entirely on the underlying cause, not the ALP value itself.