Treatment of Hypoparathyroidism
The standard treatment for hypoparathyroidism consists of oral calcium supplementation and active vitamin D (calcitriol or alfacalcidol), with dosing adjusted to maintain serum calcium in the low-normal range. 1
Initial Management
Calcium Supplementation
- Calcium carbonate is preferred (40% elemental calcium by weight)
- Calcium citrate (21% elemental calcium) should be used in patients with achlorhydria or those on proton pump inhibitors 2
- Dosing should be divided throughout the day to maximize absorption
Active Vitamin D Therapy
- Initial dosing recommendations:
- Calcitriol: 0.5-1.0 μg daily (20-30 ng/kg body weight daily) OR
- Alfacalcidol: 1.0 μg daily (30-50 ng/kg body weight daily) 1
- Dose should be adjusted based on serum calcium levels and symptoms
- Many clinicians prefer to uptitrate active vitamin D to reduce the amount of calcium supplementation needed 2
Monitoring Parameters
Biochemical Monitoring
- Serum calcium: Initially weekly, then monthly when stable
- Serum phosphorus: Maintain within normal range
- Urinary calcium: Keep within normal range to prevent nephrocalcinosis
- 25(OH) vitamin D: Check before initiating treatment 1
Monitoring Frequency
| Parameter | Frequency |
|---|---|
| Calcium & Phosphorus | Initially weekly, then monthly when stable |
| Urinary calcium | Every 3-6 months |
| Renal function | Every 6-12 months |
Management of Complications
Prevention of Nephrocalcinosis
- Keep urinary calcium levels within normal range
- Ensure regular water intake
- Consider potassium citrate administration
- Limit sodium intake 1
Management of Severe Hypocalcemia
For symptomatic hypocalcemia (tetany, seizures, QT prolongation):
- IV calcium gluconate 50-100 mg/kg as a single dose 1
- Follow with oral calcium and vitamin D therapy
Advanced Treatment Options
Refractory Hypoparathyroidism
For cases unresponsive to conventional therapy:
Parathyroid Hormone Replacement:
Parathyroid Gland Autotransplantation:
- May be considered in surgical cases where parathyroid tissue is identified during thyroidectomy 6
Common Pitfalls to Avoid
- Overtreatment: Excessive vitamin D and calcium can lead to hypercalciuria, nephrocalcinosis, and ectopic calcifications
- Undertreatment: Inadequate therapy can result in symptomatic hypocalcemia
- Ignoring vitamin D status: Vitamin D deficiency can complicate management 1
- Biotin interference: Can affect PTH assay results, leading to incorrect dosing decisions 1
- Magnesium deficiency: Can exacerbate hypocalcemia and should be corrected if present
Special Considerations
- Check magnesium levels in patients with difficult-to-control hypocalcemia
- Consider reducing calcium-based phosphate binders if hyperphosphatemia is present
- Avoid aggressive calcium supplementation in patients with hypercalciuria
- Adjust treatment plans before surgery; decrease or stop active vitamin D if patients are immobilized for extended periods 7
Hypoparathyroidism management requires careful balance of calcium and vitamin D supplementation to maintain serum calcium in the low-normal range while avoiding complications of treatment. PTH replacement therapy represents an emerging option for patients with difficult-to-control disease.