What is the treatment for abnormal Parathyroid Hormone (PTH) levels?

Treatment of Abnormal Parathyroid Hormone (PTH) Levels

The treatment of abnormal PTH depends critically on whether you are dealing with primary hyperparathyroidism (elevated PTH with hypercalcemia), secondary hyperparathyroidism (elevated PTH with normal/low calcium in CKD), or hypoparathyroidism (low PTH with hypocalcemia)—each requires fundamentally different management strategies.

Initial Diagnostic Confirmation

Before initiating any treatment, you must establish the specific diagnosis:

• Measure serum calcium (corrected for albumin) and intact PTH simultaneously to distinguish between primary and secondary causes 1, 2
• Assess vitamin D status (25-OH vitamin D) as deficiency can cause secondary hyperparathyroidism and complicate PTH interpretation 3, 1, 2
• Check serum phosphorus to help differentiate primary hyperparathyroidism (low phosphorus) from secondary hyperparathyroidism in CKD (high phosphorus) 3

Critical caveat: PTH assays vary significantly between laboratories and different assay generations have variable sensitivity to PTH fragments—always use assay-specific reference values when interpreting results 1, 2.

Treatment of Primary Hyperparathyroidism (High PTH + High Calcium)

Surgical Management (Definitive Treatment)

Parathyroidectomy is the only curative treatment for primary hyperparathyroidism and should be performed in patients with symptomatic disease (kidney stones, bone pain, fractures, neuromuscular symptoms) or those meeting specific criteria including impaired kidney function (GFR <60 mL/min/1.73 m²) or osteoporosis on DEXA scan 3, 4, 2.

Surgical approach options:

• Minimally invasive parathyroidectomy (MIP) offers shorter operating times, faster recovery, and decreased perioperative costs compared to bilateral neck exploration 4, 2
• MIP requires confident preoperative localization of a single parathyroid adenoma using ultrasound and/or dual-phase 99mTc-sestamibi scintigraphy with SPECT/CT, plus intraoperative PTH monitoring 3, 4, 2
• Bilateral neck exploration (BNE) remains necessary for cases with discordant/nonlocalizing imaging or suspected multigland disease 4
• For MEN2 patients, surgical approach may include total four-gland parathyroidectomy with autotransplantation of parathyroid tissue to the neck or forearm, often with transcervical thymectomy 3

Postoperative Monitoring

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

Treatment of Secondary Hyperparathyroidism (High PTH + Normal/Low Calcium in CKD)

Initial Medical Management

For CKD patients with progressively rising or persistently elevated PTH above the upper normal limit, evaluate and correct modifiable factors first 3:

• Dietary phosphate restriction 4, 2
• Phosphate binders (restrict dose of calcium-based binders if hypercalcemia develops) 3, 4, 2
• Correction of hypocalcemia with calcium supplementation (provide calcium carbonate when oral intake is possible) 1, 4, 2
• Vitamin D sterols (calcitriol, paricalcitol, doxercalciferol) with dosage adjusted according to severity of hyperparathyroidism 3, 4, 2

Vitamin D Sterol Dosing

For CKD G3a-G5 not on dialysis:

• Reserve calcitriol and vitamin D analogs for patients with CKD G4-G5 with severe and progressive hyperparathyroidism 3

For peritoneal dialysis patients:

• Oral calcitriol 0.5-1.0 μg or doxercalciferol 2.5-5.0 μg given 2-3 times weekly 4

Target PTH Levels

• For CKD G5D (dialysis patients), maintain intact PTH levels in the range of approximately 2 to 9 times the upper normal limit for the assay 3
• Marked changes in PTH levels in either direction within this range should prompt initiation or change in therapy 3

Monitoring During Treatment

Strict monitoring is essential 1, 4, 2:

• Serum calcium and phosphorus every 2 weeks for 1 month after initiation or dose increase, then monthly 3, 1, 4
• PTH monthly for at least 3 months, then every 3 months once target levels achieved 3, 1, 4
• Do not initiate or continue vitamin D treatment if serum phosphorus exceeds 6.5 mg/dL due to risk of further elevating phosphorus 3

Calcimimetics (Cinacalcet)

For persistent secondary hyperparathyroidism despite initial therapy, consider cinacalcet 4, 2:

• Start at 30 mg once daily and titrate no more frequently than every 2-4 weeks to target iPTH levels of 150-300 pg/mL 2
• Use with caution due to potential hypocalcemia and increased QT interval 4, 2

Important distinction: Calcimimetics are NOT indicated in pseudohypoparathyroidism, as the problem is resistance to PTH, not excess production 1.

Surgical Management for Refractory Cases

Parathyroidectomy should be recommended for severe hyperparathyroidism (persistent serum levels of intact PTH >800 pg/mL) associated with hypercalcemia and/or hyperphosphatemia refractory to medical therapy 3, 4, 2.

Surgical options include:

• Subtotal parathyroidectomy
• Total parathyroidectomy with parathyroid tissue autotransplantation
• Total parathyroidectomy (but NOT recommended for patients who may subsequently receive a kidney transplant, as control of serum calcium levels may be problematic) 4

Treatment of Hypoparathyroidism (Low PTH + Low Calcium)

Calcium and Vitamin D Supplementation

• Provide calcium carbonate when oral intake is possible 1
• Monitor calcium and phosphorus séricos every 2 weeks during the first month after starting or increasing doses, then monthly 1
• Monitor PTH monthly for at least 3 months, then every 3 months once target levels are achieved 1

PTH Replacement Therapy (Teriparatide)

Teriparatide is a recombinant PTH analog (PTH 1-34) indicated for osteoporosis treatment, not hypoparathyroidism 5:

• Recommended dosage is 20 mcg subcutaneously once daily 5
• Administer as subcutaneous injection into the thigh or abdominal region 5
• Use for more than 2 years during a patient's lifetime should only be considered if a patient remains at or has returned to having a high risk for fracture 5
• Avoid in patients with increased risk of osteosarcoma including those with open epiphyses, metabolic bone diseases including Paget's disease, bone metastases, or history of skeletal malignancies 5

Common Pitfalls to Avoid

• Never use absolute PTH cutoff values without specifying the assay used, as different generations of assays have variable sensitivity to PTH fragments 1, 2
• Do not overlook vitamin D deficiency, as it can cause secondary hyperparathyroidism and complicate PTH interpretation 3, 1, 2
• Avoid imaging in the absence of biochemical evidence of disease in MEN2 patients 3
• Do not continue vitamin D treatment if serum phosphorus exceeds 6.5 mg/dL due to risk of hypercalcemia and vascular calcification 3
• Beware of adynamic bone disease in dialysis patients with intact PTH levels below 150 pg/mL, particularly with intermittent calcitriol therapy 3