How to manage hyperparathyroidism (high PTH levels)?

Management of Hyperparathyroidism

The management of elevated parathyroid hormone (PTH) levels should be tailored to the specific type of hyperparathyroidism, with treatment options ranging from vitamin D therapy and phosphate control to calcimimetics or surgical intervention depending on disease severity and underlying etiology. 1

Types of Hyperparathyroidism and Initial Assessment

• Secondary hyperparathyroidism is characterized by normal or low serum calcium with elevated PTH, commonly seen in chronic kidney disease (CKD), vitamin D deficiency, and malabsorption syndromes 1
• Tertiary hyperparathyroidism occurs when parathyroid glands become autonomous after longstanding secondary hyperparathyroidism, often following renal transplantation 2
• Initial evaluation should include measurement of serum calcium, phosphorus, 25-hydroxyvitamin D, and intact PTH levels to determine the type and cause of hyperparathyroidism 3

Management of Secondary Hyperparathyroidism in CKD

CKD Stages 3-4

• Control serum phosphorus through dietary phosphorus restriction and phosphate binders, targeting serum phosphorus within the normal range 1, 4
• For patients with vitamin D deficiency (25-hydroxyvitamin D <30 ng/mL), initiate supplementation with ergocalciferol or cholecalciferol 5
• For patients with elevated PTH despite vitamin D repletion, initiate active vitamin D analogs (calcitriol, paricalcitol, or doxercalciferol) 5
• For paricalcitol, the recommended starting dose is:
  • 1 mcg daily or 2 mcg three times weekly if baseline iPTH ≤500 pg/mL
  • 2 mcg daily or 4 mcg three times weekly if baseline iPTH >500 pg/mL 6

CKD Stage 5 (Dialysis)

• For hemodialysis or peritoneal dialysis patients with iPTH >300 pg/mL, administer active vitamin D sterols to reduce iPTH to 150-300 pg/mL 5
• For paricalcitol, calculate initial dose using formula: Dose (mcg) = baseline iPTH (pg/mL) divided by 80 6
• Intravenous administration of calcitriol is more effective than oral administration for hemodialysis patients 5, 4
• Consider paricalcitol or doxercalciferol in patients with elevated calcium or phosphorus levels 5

Dose Adjustments and Monitoring

• Monitor serum calcium and phosphorus levels at least every 2 weeks for 1 month after initiating therapy, then monthly thereafter 5
• Monitor plasma PTH monthly for at least 3 months and then every 3 months once target levels are achieved 5
• Adjust vitamin D sterol dosage based on iPTH, calcium, and phosphorus levels 6:
  • If iPTH decreases by <30% or remains unchanged: Increase dose
  • If iPTH decreases by 30-60%: Maintain dose
  • If iPTH decreases by >60% or falls below 60 pg/mL: Decrease dose 6
• Hold vitamin D therapy if:
  • Serum calcium exceeds 9.5 mg/dL (2.37 mmol/L)
  • Serum phosphorus rises above 4.6 mg/dL (1.49 mmol/L) 5

Surgical Management

• Consider parathyroidectomy for severe hyperparathyroidism with hypercalcemia that precludes medical therapy 1, 4
• Surgical options include:
  • Total parathyroidectomy (TPTX)
  • Total parathyroidectomy with autotransplantation (TPTX+AT)
  • Subtotal parathyroidectomy (SPTX) 1, 4
• TPTX+AT has become the preferred option in many clinical centers due to lower risk of permanent hypoparathyroidism 1
• For tertiary hyperparathyroidism, surgery is the primary treatment 2

Special Considerations and Pitfalls

• Excessive suppression of PTH can lead to adynamic bone disease, which may increase risk of fractures and vascular calcifications 7, 8
• In pediatric dialysis patients, extremely high PTH levels (>500 pg/mL) have been associated with impaired growth, cardiovascular comorbidities, and increased mortality 8
• Avoid vitamin D sterols in patients with rapidly worsening kidney function or those who are noncompliant with medications or follow-up 5
• For nutritional vitamin D deficiency causing secondary hyperparathyroidism, target 25-hydroxyvitamin D levels >30 ng/mL 3
• Calcium citrate may be preferred over calcium carbonate in patients with suspected malabsorption 3

Post-Treatment Monitoring

• For patients on medical therapy, continue monitoring serum calcium and phosphorus monthly and iPTH every 3 months 4
• For post-parathyroidectomy patients, monitor ionized calcium every 4-6 hours for the first 48-72 hours 4
• Provide calcium supplementation if hypocalcemia develops after parathyroidectomy 4