What is the best next step for a patient with end-stage kidney disease, osteitis fibrosa cystica, and severely elevated parathyroid hormone (PTH) levels, currently on cinacalcet (Sensipar) and calcitriol (Vitamin D3), presenting with a femur neck fracture?

From the Guidelines

The best next step for this patient is urgent parathyroidectomy after surgical stabilization of the femur neck fracture. The patient should be prepared for surgery with optimization of calcium levels, and the surgical team should plan for a subtotal parathyroidectomy or total parathyroidectomy with autotransplantation. Current medical therapy with cinacalcet and calcitriol has failed to adequately control the secondary hyperparathyroidism, as evidenced by the development of osteitis fibrosa cystica and pathologic fracture, with a serum parathyroid hormone (PTH) level of 1100 pg/mL, which is significantly above the target range of 130-585 pg/mL 1.

Following parathyroidectomy, the patient will require careful monitoring of calcium levels, as hungry bone syndrome commonly occurs postoperatively. Calcium supplementation (typically 1-2g elemental calcium daily) and calcitriol (0.25-1mcg daily) should be initiated promptly after surgery, with dose adjustments based on serum calcium levels 1. Cinacalcet should be discontinued before surgery. This surgical approach is necessary because severe hyperparathyroidism has led to significant bone disease despite medical management, and parathyroidectomy will address the underlying cause of bone mineral loss, potentially allowing for fracture healing and preventing future fractures.

The most recent evidence from 2025 suggests that parathyroidectomy is associated with lower mortality than the use of calcimimetics in patients with end-stage kidney disease, and it is more effective in controlling hypercalcemia and increasing bone mineral density compared to cinacalcet 1. Continued medical management alone would be insufficient to reverse the established bone disease and prevent further skeletal complications in this patient with end-stage kidney disease.

Key considerations for the patient's management include:

• Monitoring of calcium levels every 4 to 6 hours for the first 48 to 72 hours after surgery, and then twice daily until stable 1
• Initiation of calcium gluconate infusion if blood levels of ionized or corrected total calcium fall below normal 1
• Discontinuation of cinacalcet before surgery and adjustment of calcitriol dose based on serum calcium levels 1
• Consideration of the patient's peripheral arterial disease and end-stage kidney disease in the surgical planning and postoperative management.

From the FDA Drug Label

Cinacalcet tablets are indicated for the treatment of secondary hyperparathyroidism (HPT) in adult patients with chronic kidney disease (CKD) on dialysis [see Clinical Studies (14. 1)]. The recommended starting oral dose of cinacalcet tablets is 30 mg once daily. Serum calcium and serum phosphorus should be measured within 1 week and intact parathyroid hormone (iPTH) should be measured 1 to 4 weeks after initiation or dose adjustment of cinacalcet tablets [see Dosage and Administration (2. 3)]. Cinacalcet tablets should be titrated no more frequently than every 2 to 4 weeks through sequential doses of 30,60,90,120, and 180 mg once daily to target iPTH levels of 150 to 300 pg/mL.

The patient's current parathyroid hormone (PTH) level is 1100 pg/mL, which is above the target range. The patient is already on cinacalcet (180 mg daily), which is the maximum recommended dose. Given the patient's severely elevated PTH levels and the fact that they are already on the maximum dose of cinacalcet, the best next step would be to evaluate for parathyroidectomy.

• The patient's osteitis fibrosa cystica and elevated PTH levels despite maximum medical therapy suggest that surgical intervention may be necessary.
• Increasing calcitriol or switching from peritoneal dialysis to hemodialysis may not be sufficient to control the patient's PTH levels, and replacing sevelamer with calcium acetate may not address the underlying issue of severe hyperparathyroidism. 2

From the Research

Patient's Condition

The patient has end-stage kidney disease, osteitis fibrosa cystica, and severely elevated parathyroid hormone (PTH) levels, currently on cinacalcet and calcitriol, presenting with a femur neck fracture. The patient's laboratory studies show:

• Serum calcium 10.2 mg/dL
• Serum phosphorous 4.5 mg/dL
• Serum albumin 3.8 g/dL
• Serum parathyroid hormone 1100 pg/mL
• Serum 25-hydroxyvitamin D 30 ng/mL

Treatment Options

Considering the patient's condition and laboratory results, the following treatment options are available:

• Evaluate for parathyroidectomy
• Increase calcitriol to 1 mg daily
• Switch from peritoneal dialysis to hemodialysis
• Replace sevelamer with calcium acetate

Best Next Step

Based on the studies, the best next step for the patient would be to:

• Evaluate for parathyroidectomy 3, 4, 5, 6 The patient's severely elevated PTH levels and osteitis fibrosa cystica suggest that parathyroidectomy may be necessary to control the patient's condition. Cinacalcet and calcitriol have been shown to be effective in reducing PTH levels, but the patient's PTH levels remain severely elevated despite treatment 4, 6. Parathyroidectomy has been shown to be effective in reducing PTH levels and improving bone histology in patients with secondary hyperparathyroidism 5.

Key Points

• The patient's PTH levels are severely elevated despite treatment with cinacalcet and calcitriol
• Parathyroidectomy may be necessary to control the patient's condition
• Cinacalcet and calcitriol have been shown to be effective in reducing PTH levels, but may not be sufficient in this case
• The patient's osteitis fibrosa cystica and femur neck fracture suggest that prompt treatment is necessary to prevent further complications 3, 5