What is the treatment for hyperparathyroidism?

Treatment of Hyperparathyroidism

Surgical parathyroidectomy is the definitive treatment for primary hyperparathyroidism, while secondary hyperparathyroidism in chronic kidney disease (CKD) should be managed initially with medical therapy including phosphate binders, calcium supplementation, and vitamin D sterols. 1

Types of Hyperparathyroidism and Their Management

Primary Hyperparathyroidism

Primary hyperparathyroidism occurs when parathyroid glands autonomously overproduce parathyroid hormone (PTH), typically resulting in hypercalcemia. It is most commonly due to:

• Single parathyroid adenoma (80%)
• Multiple adenomas or hyperplasia (15-20%)
• Parathyroid carcinoma (<1%) 1

Surgical Management:

• First-line treatment: Parathyroidectomy
• Surgical approaches:
  • Bilateral neck exploration (BNE): Traditional approach where all parathyroid glands are identified
  • Minimally invasive parathyroidectomy (MIP): Unilateral operation with limited dissection for targeted removal of affected gland(s) 1

MIP requires precise preoperative localization of the adenoma, typically using:

• 99mTc-sestamibi scan (highest sensitivity)
• Ultrasound
• CT scan or MRI 1

Secondary Hyperparathyroidism in CKD

Secondary hyperparathyroidism develops due to chronic kidney disease, resulting from:

• Hyperphosphatemia
• Calcitriol deficiency
• Hypocalcemia 2

Medical Management (First-line):

1. Phosphate control:

   • Dietary phosphate restriction
   • Phosphate binders

2. Calcium management:

   • Calcium supplementation for hypocalcemia

3. Vitamin D therapy:

   • Calcitriol: Initial dose 20-30 ng/kg body weight daily
   • Alfacalcidol: Initial dose 30-50 ng/kg body weight daily 1

4. Calcimimetics (for persistent hyperparathyroidism):

   • Cinacalcet: Increases sensitivity of calcium-sensing receptor
   • Caution: May cause hypocalcemia and increased QT interval 1, 3

Surgical Management (When Medical Therapy Fails):

Parathyroidectomy is indicated when:

• Severe hyperparathyroidism persists (PTH >800 pg/mL)
• Associated with hypercalcemia or hyperphosphatemia refractory to medical therapy
• Calciphylaxis with elevated PTH levels (>500 pg/mL) 1

Tertiary Hyperparathyroidism

Occurs when parathyroid glands continue to oversecrete PTH despite correction of the primary disorder (often after kidney transplantation) 2.

Treatment: Primarily surgical, with options similar to those for secondary hyperparathyroidism 2

Surgical Approaches

For Primary Hyperparathyroidism:

• Minimally invasive parathyroidectomy is preferred when a single adenoma is confidently localized
• Bilateral neck exploration is necessary for discordant imaging or suspected multigland disease 1

For Secondary/Tertiary Hyperparathyroidism:

Three main approaches:

1. Subtotal parathyroidectomy: Removal of 3.5 glands
2. Total parathyroidectomy with autotransplantation: All glands removed with reimplantation of tissue (usually in forearm)
3. Total parathyroidectomy: All glands removed 1

All approaches have comparable outcomes, with the choice often depending on surgeon preference and patient factors. Total parathyroidectomy may not be suitable for patients who may receive a kidney transplant in the future 1.

Post-Surgical Management

After parathyroidectomy:

• Monitor ionized calcium every 4-6 hours for first 48-72 hours, then twice daily until stable
• If calcium falls below normal (<0.9 mmol/L):
  • Initiate calcium gluconate infusion (1-2 mg elemental calcium per kg body weight per hour)
  • When oral intake is possible, provide calcium carbonate 1-2g three times daily and calcitriol up to 2g/day
• Adjust phosphate binders based on serum phosphorus levels 1

Special Considerations

For Persistent or Recurrent Hyperparathyroidism:

• Imaging with 99mTc-sestamibi scan, ultrasound, CT, or MRI is essential before reoperation 1
• Reoperation has lower cure rates and higher complication risks than initial surgery 1

For Patients Unable to Undergo Surgery:

• Bisphosphonates: Reduce bone resorption
• Hormone replacement therapy: For postmenopausal women
• Calcimimetics: Inhibit PTH secretion 4

Monitoring and Follow-up

• For CKD patients: Monitor serum calcium and phosphorus monthly, PTH every 1-3 months
• After parathyroidectomy: Regular monitoring of calcium levels to detect hypoparathyroidism or recurrence
• For patients on calcimimetics: Monitor for hypocalcemia, especially in the first week of treatment 1, 3

By following these treatment guidelines, the morbidity and mortality associated with hyperparathyroidism can be significantly reduced, improving quality of life for affected patients.