Management of Intact PTH Elevation

Initial Diagnostic Evaluation

The American Journal of Kidney Diseases recommends measuring serum calcium, phosphorus, 25-OH vitamin D, and kidney function to determine the underlying cause of elevated intact PTH 1
If calcium is normal or low with elevated PTH, evaluate for secondary causes 1
If chronic kidney disease is present, stage-specific PTH targets apply 2, 3

For CKD Stage 3, the target PTH is 35-70 pg/mL 2
For CKD Stage 4, the target PTH is 70-110 pg/mL 2
For CKD Stage 5, the target PTH is 150-300 pg/mL 2, 5
When PTH exceeds target levels, restrict dietary phosphate intake, ensure 25-OH vitamin D levels ≥30 ng/mL, and initiate active vitamin D sterol if corrected calcium <9.5 mg/dL and phosphorus <4.6 mg/dL 2, 3, 4
The starting dose for active vitamin D sterol is calcitriol 0.25 mcg daily or doxercalciferol 2.5 mcg daily 2

Surgery is indicated when PTH >800 pg/mL with hypercalcemia and/or hyperphosphatemia refractory to medical therapy, or when there are symptoms such as recurrent renal stones, bone disease, or fractures 1, 7
Subtotal parathyroidectomy or total parathyroidectomy with autotransplantation are surgical options 1, 7

For CKD Stages 3-4 on active vitamin D, monitor calcium and phosphorus monthly for the first 3 months, then every 3 months, and PTH every 3 months for 6 months, then every 3 months thereafter 2, 3
For CKD Stage 5 on active vitamin D, monitor calcium and phosphorus every 2 weeks for 1 month, then monthly, and PTH monthly for 3 months, then every 3 months once target achieved 2, 5
For primary hyperparathyroidism, monitor calcium and phosphorus monthly for the first 3 months, then every 3 months, and PTH every 3 months for 6 months, then every 3-6 months 1

Oversuppression of PTH below 100 pg/mL in dialysis patients can cause adynamic bone disease, and if PTH falls below target range, hold vitamin D therapy until PTH rises, then resume at half the previous dose 2, 3, 6
Do not delay surgery in patients with recurrent renal stones and hyperparathyroidism, as progressive renal damage occurs 1, 7
Dialysate calcium concentration should be 2.5 mEq/L (1.25 mmol/L) to minimize calcium loading while using calcium-based phosphate binders and vitamin D 5, 6