What is the treatment for high parathyroid hormone (PTH) levels?

Treatment for High Parathyroid Hormone (PTH) Levels

The treatment of hyperparathyroidism depends on the specific type (primary, secondary, or tertiary) with surgical intervention being the definitive treatment for primary hyperparathyroidism, while secondary hyperparathyroidism in chronic kidney disease requires a stepwise approach starting with phosphorus restriction, vitamin D therapy, and potentially calcimimetics, with parathyroidectomy reserved for severe cases unresponsive to medical management. 1

Types of Hyperparathyroidism

Primary Hyperparathyroidism

• Characterized by autonomous PTH secretion, usually from a parathyroid adenoma
• Treatment approach:
  • Surgical referral to a high-volume parathyroid surgeon is recommended for better outcomes 1
  • Parathyroidectomy is the definitive treatment
  • For patients unable to undergo surgery, medical management with cinacalcet is indicated 2

Secondary Hyperparathyroidism

• Occurs as a compensatory response to low calcium levels, commonly in chronic kidney disease (CKD)
• Treatment algorithm:
  1. Correct vitamin D deficiency with nutritional vitamin D supplements 1
  2. Control phosphate levels through dietary restriction (800-1,000 mg/day) and phosphate binders 1
  3. Active vitamin D therapy (calcitriol or vitamin D analogs) for more advanced cases 1
  4. Calcimimetics (cinacalcet) for persistent hyperparathyroidism despite above measures 1, 2
  5. Parathyroidectomy for severe cases unresponsive to medical therapy 1

Tertiary Hyperparathyroidism

• Results from longstanding secondary hyperparathyroidism that has become autonomous
• Treatment:
  • Parathyroidectomy is recommended for persistent hypercalcemic hyperparathyroidism despite optimized medical therapy 3
  • Options include subtotal parathyroidectomy, total parathyroidectomy with autotransplantation, or total parathyroidectomy without autotransplantation 1

Specific Treatment Recommendations Based on PTH Levels

PTH Level	Treatment Approach
Mildly elevated	Optimize calcium and vitamin D levels
150-300 pg/mL	Maintain current therapy
300-500 pg/mL	Increase vitamin D sterols, adjust phosphate binders
500-800 pg/mL	Higher doses of vitamin D sterols, consider adding cinacalcet
>800 pg/mL	Consider parathyroidectomy if medical therapy fails

Medication Details

Cinacalcet

• Starting dose: 30 mg once daily for secondary hyperparathyroidism in CKD patients on dialysis 2
• Titration: Increase dose every 2-4 weeks through sequential doses of 30,60,90,120, and 180 mg once daily 2
• Target: iPTH levels of 150-300 pg/mL 2
• Monitoring: Check serum calcium within 1 week and iPTH 1-4 weeks after initiation or dose adjustment 2
• Important caveat: Not indicated for CKD patients who are not on dialysis due to increased risk of hypocalcemia 2

Vitamin D Therapy

• For secondary hyperparathyroidism:
  • Initial dose of calcitriol: 20-30 ng/kg body weight daily 3
  • Initial dose of alfacalcidol: 30-50 ng/kg body weight daily 3
  • Alternative starting dose: 0.5 μg daily of calcitriol or 1 μg of alfacalcidol in patients >12 months old 3

Monitoring Recommendations

• Calcium and phosphorus levels: Check within 1 week after starting or adjusting calcimimetic therapy 1
• iPTH levels: Check 1-4 weeks after initiation or dose adjustment of calcimimetics 1
• Regular monitoring frequency based on CKD stage:
  • Stage 3 CKD: Calcium & phosphorus every 6-12 months
  • Stage 4 CKD: Calcium & phosphorus every 3-6 months, PTH every 3-6 months
  • Stage 5 CKD: Calcium & phosphorus every 1-3 months, PTH every month
  • Dialysis patients: Calcium & phosphorus monthly, PTH monthly 1

Important Caveats and Pitfalls

• Vitamin D status: Always check vitamin D levels, as deficiency can cause secondary hyperparathyroidism and affect PTH levels 1
• Hypercalcemia risk: Monitor calcium levels closely when using vitamin D therapy to avoid hypercalcemia 3
• Nephrocalcinosis risk: Keep calciuria levels within normal range and avoid large doses of phosphate supplements 3
• Biotin interference: Be aware that biotin supplements can interfere with PTH assays, causing falsely high or low results 1
• Hungry bone syndrome: Watch for severe hypocalcemia after parathyroidectomy, especially in patients with significant bone disease 1
• GH therapy interaction: In patients receiving growth hormone therapy, GH should be withheld if PTH levels exceed 500 pg/mL 3

By following this structured approach to managing elevated PTH levels based on the underlying cause and severity, clinicians can effectively control hyperparathyroidism and prevent its complications.