What is the treatment for hyperparathyroidism?

Treatment for Hyperparathyroidism

Parathyroidectomy is the definitive treatment for primary hyperparathyroidism, while the approach for secondary and tertiary hyperparathyroidism depends on the underlying cause and severity. 1, 2

Types of Hyperparathyroidism and Their Management

Primary Hyperparathyroidism

Primary hyperparathyroidism occurs due to autonomous hypersecretion of parathyroid hormone (PTH), usually from a solitary parathyroid adenoma.

Indications for Parathyroidectomy:

• Presence of symptoms
• Age ≤50 years
• Serum calcium >1 mg/dL above upper limit of normal
• Osteoporosis
• Creatinine clearance <60 mL/min/1.73m²
• Nephrolithiasis or nephrocalcinosis
• Hypercalciuria 2

Surgical Options:

• Bilateral cervical exploration (95-98% cure rate)
• Minimally invasive parathyroidectomy (for well-localized single adenomas)
• Total parathyroidectomy with autotransplantation 3, 4

For patients unable to undergo surgery, cinacalcet is FDA-approved for treatment of hypercalcemia in primary hyperparathyroidism, starting at 30 mg twice daily and titrating every 2-4 weeks as needed to normalize calcium levels 5.

Secondary Hyperparathyroidism

Secondary hyperparathyroidism occurs due to compensatory PTH elevation in response to hypocalcemia, most commonly in chronic kidney disease (CKD).

Management in CKD:

1. Monitor calcium, phosphorus, and PTH levels according to CKD stage:

   • Stage 3: Every 6-12 months
   • Stage 4: Every 3-6 months
   • Stage 5: Every 1-3 months
   • Dialysis: Monthly 1

2. Target PTH levels:

   • CKD G3: <70 pg/mL
   • CKD G4: <110 pg/mL
   • CKD G5: <300 pg/mL
   • CKD G5D (dialysis): 150-600 pg/mL 1

3. Treatment algorithm:

   • First: Correct hyperphosphatemia, hypocalcemia, and vitamin D deficiency
   • For PTH >300 pg/mL in dialysis patients: Initiate active vitamin D sterols
   • For PTH 300-500 pg/mL: Increase vitamin D sterols, adjust phosphate binders
   • For PTH 500-800 pg/mL: Higher doses of vitamin D sterols, consider adding cinacalcet
   • For PTH >800 pg/mL: Consider parathyroidectomy if medical therapy fails 1

4. Cinacalcet for dialysis patients:

   • Starting dose: 30 mg once daily
   • Titrate every 2-4 weeks through sequential doses of 30,60,90,120, and 180 mg once daily
   • Target iPTH: 150-300 pg/mL
   • Monitor serum calcium closely 5

Tertiary Hyperparathyroidism

Tertiary hyperparathyroidism occurs when parathyroid glands become autonomous after longstanding secondary hyperparathyroidism, often after renal transplantation.

Management:

• Primary treatment is surgical parathyroidectomy
• Options include total parathyroidectomy with or without autotransplantation, subtotal parathyroidectomy, or limited parathyroidectomy
• Transcervical thymectomy should be performed with parathyroidectomy 6, 4

Special Considerations

Calcium Monitoring

• After establishing maintenance dose, monitor serum calcium monthly for secondary hyperparathyroidism with CKD on dialysis
• If serum calcium falls below 8.4 mg/dL but remains above 7.5 mg/dL, or if symptoms of hypocalcemia occur, use calcium-containing phosphate binders and/or vitamin D sterols
• If serum calcium falls below 7.5 mg/dL, withhold cinacalcet until levels reach 8 mg/dL 5

Multiple Endocrine Neoplasia (MEN)

• In MEN type 1 patients with hyperparathyroidism, more extensive surgery is typically required
• Either subtotal parathyroidectomy (removal of at least 3-3.5 glands) or total parathyroidectomy with autologous grafting is recommended
• Transcervical thymectomy must be performed with both procedures 4

Common Pitfalls and Caveats

1. Failure to diagnose MEN syndromes: Always consider genetic testing in young patients or those with family history of endocrine tumors.

2. Inadequate preoperative localization: Proper imaging studies are essential before reoperation for persistent or recurrent hyperparathyroidism.

3. Incomplete surgical exploration: Transcervical thymectomy should be performed during parathyroidectomy to remove potential ectopic parathyroid tissue.

4. Hypocalcemia after surgery: Monitor calcium levels closely and provide supplementation as needed.

5. Cinacalcet contraindications: Not indicated for patients with CKD who are not on dialysis due to increased risk of hypocalcemia 5.

6. Calcium-based phosphate binders: Avoid in patients with hypercalcemia or low PTH levels 1.