Treatment of Hyperparathyroidism

Surgical excision of abnormal parathyroid tissue is the only definitive cure for primary hyperparathyroidism (PHPT). 1, 2

Types of Hyperparathyroidism and Treatment Approaches

Minimally invasive parathyroidectomy (MIP) and bilateral neck exploration (BNE) are both effective surgical approaches, with MIP offering shorter operating times, faster recovery, and decreased costs 2
MIP requires confident preoperative localization of a single parathyroid adenoma and intraoperative PTH monitoring 2
BNE is necessary for cases with discordant/nonlocalizing imaging or suspected multigland disease 2
For patients with asymptomatic PHPT who are older than 50 years with serum calcium less than 1 mg/dL above normal and no evidence of skeletal or kidney disease, observation may be appropriate 3
Cinacalcet is indicated for hypercalcemia in patients with primary hyperparathyroidism who cannot undergo parathyroidectomy 4

Initial treatment includes dietary phosphate restriction, phosphate binders, correction of hypocalcemia, and vitamin D supplementation 5
For patients with chronic kidney disease (CKD), target serum phosphorus within the normal range 5
Vitamin D therapy with intermittent intravenous calcitriol or paricalcitol is recommended for hemodialysis patients 5
For persistent secondary hyperparathyroidism, calcimimetics (cinacalcet) may be considered, with caution due to potential hypocalcemia 5, 4
Cinacalcet is specifically indicated for secondary hyperparathyroidism in adult patients with CKD on dialysis, but not for those not on dialysis due to increased risk of hypocalcemia 4

Occurs when parathyroid glands continue to oversecrete PTH despite correction of the primary disorder (typically after renal transplant) 6
Surgical intervention is the primary treatment for persistent hypercalcemia and/or increased PTH 6
Surgical options include total parathyroidectomy with or without autotransplantation, subtotal parathyroidectomy, or limited parathyroidectomy 6

Before surgery, imaging with ultrasound and/or dual-phase 99mTc-sestamibi scintigraphy with SPECT/CT is highly sensitive for localizing parathyroid adenomas 1
For reoperative cases, additional imaging with CT scan or MRI should be performed to identify postoperative changes 2
Measure 25-OH Vitamin D levels to exclude hypovitaminosis D as a concomitant secondary cause of hyperparathyroidism 1

For patients who cannot undergo surgery, medical options include:
- Cinacalcet (calcimimetic) - FDA approved for hypercalcemia in PHPT patients who cannot undergo parathyroidectomy 4
- Bisphosphonates - can help manage bone disease 7
- Hormone replacement therapy in appropriate candidates 7

Cinacalcet starting dose is 30 mg once daily, titrated every 2-4 weeks through sequential doses of 30,60,90,120, and 180 mg once daily to target iPTH levels of 150-300 pg/mL 4
Monitor serum calcium and phosphorus within 1 week and iPTH 1-4 weeks after initiation or dose adjustment 4
Vitamin D supplementation: aim for 25-OH vitamin D levels >20 ng/ml (50 mmol/l) 1
Ensure adequate dietary calcium intake with dietary evaluation 1

For elevated PTH levels while on therapy with oral phosphate and active vitamin D, increase the dose of active vitamin D and/or decrease the dose of oral phosphate supplements 1
In cases of persistent hypercalciuria and/or hypercalcaemia, reduce or stop active vitamin D and phosphate supplements 1
For severe hyperparathyroidism despite normocalcaemia or hypercalcaemic hyperparathyroidism unresponsive to other treatments, calcimimetics may be considered 1
For persistent hypercalcaemic hyperparathyroidism, parathyroid resection should be considered 1

Monitor ionized calcium every 4-6 hours for the first 48-72 hours after surgery, then twice daily until stable 2, 5
Initiate calcium gluconate infusion and adjust phosphate binders as needed based on serum phosphorus levels 5

In patients with X-linked hypophosphatemia and normocalcaemic hyperparathyroidism, active vitamin D might be given without phosphate supplements if careful follow-up is guaranteed 1
For patients switching from etelcalcetide to cinacalcet, discontinue etelcalcetide for at least 4 weeks prior to starting cinacalcet, and ensure corrected serum calcium is at or above the lower limit of normal 4