What is the initial management for hypercalcemia with elevated intact parathyroid hormone (PTH) levels?

From the Guidelines

The initial management for hypercalcemia with elevated intact parathyroid hormone (PTH) levels should focus on hydration and addressing symptoms while preparing for definitive treatment, with surgical excision of the abnormally functioning parathyroid tissue being the typical indication for treatment 1. The goal is to manage symptoms and stabilize the patient for potential surgery.

• Begin with intravenous normal saline at 200-300 mL/hour to promote calcium excretion, adjusting based on the patient's cardiovascular status and severity of hypercalcemia.
• For symptomatic patients or those with calcium levels above 12 mg/dL, consider adding a bisphosphonate such as zoledronic acid 4 mg IV or pamidronate 60-90 mg IV infused over 2-4 hours.
• Calcitonin 4 IU/kg subcutaneously every 12 hours can provide rapid but temporary calcium reduction.
• Loop diuretics like furosemide 20-40 mg IV may be added after adequate hydration is achieved.
• Cinacalcet, starting at 30 mg twice daily, can be used in patients who are poor surgical candidates. It's crucial to maintain close monitoring of serum calcium, phosphate, magnesium, and renal function during initial management. These interventions work by increasing renal calcium excretion, inhibiting bone resorption, and reducing PTH-mediated calcium release from bone, providing temporary control until definitive treatment can be implemented, as indicated by the most recent guidelines on parathyroid adenoma management 1. Surgical treatment, such as bilateral neck exploration (BNE) or minimally invasive parathyroidectomy (MIP), is the definitive approach for primary hyperparathyroidism, with the choice between BNE and MIP depending on factors like the presence of a single adenoma or multigland disease 1.

From the FDA Drug Label

Cinacalcet tablets are indicated for the treatment of hypercalcemia in adult patients with Parathyroid Carcinoma [see Clinical Studies(14.2)]. Cinacalcet tablets are indicated for the treatment of hypercalcemia in adult patients with primary HPT for whom parathyroidectomy would be indicated on the basis of serum calcium levels, but who are unable to undergo parathyroidectomy [see Clinical Studies (14.3)]. The initial management for hypercalcemia with elevated intact parathyroid hormone (PTH) levels is to treat the underlying cause, which may involve the use of cinacalcet.

• The recommended starting oral dose of cinacalcet is 30 mg twice daily for patients with parathyroid carcinoma or primary hyperparathyroidism.
• The dose of cinacalcet should be titrated every 2 to 4 weeks through sequential doses of 30 mg twice daily, 60 mg twice daily, and 90 mg twice daily, and 90 mg 3 or 4 times daily as necessary to normalize serum calcium levels 2.
• Serum calcium should be measured within 1 week after initiation or dose adjustment of cinacalcet 2.
• Monitoring for hypocalcemia is crucial, and serum calcium should be measured approximately monthly for patients with secondary hyperparathyroidism and every 2 months for patients with parathyroid carcinoma or primary hyperparathyroidism 2.

From the Research

Initial Management for Hypercalcemia with Elevated Intact Parathyroid Hormone (PTH) Levels

The initial management for hypercalcemia with elevated intact parathyroid hormone (PTH) levels involves several key steps:

• Vigorous intravenous hydration to help reduce serum calcium levels 3, 4, 5
• The use of drugs to reduce bone resorption, such as bisphosphonates (e.g., zoledronic acid or pamidronate) 3, 4, 5
• In some cases, the use of corticosteroids and calcitonin may be considered 3
• Denosumab may be used in refractory cases or in patients with kidney failure 3, 4

Etiological Investigation

Etiological investigation is mandatory in all cases of hypercalcemia to determine the underlying cause, as the definitive treatment depends on the etiology 3, 4

• Primary hyperparathyroidism (PHPT) is the most common cause of hypercalcemia, and parathyroidectomy may be considered depending on age, serum calcium level, and kidney or skeletal involvement 4, 6
• In patients with PHPT, medical management may be considered in those with mild asymptomatic disease, contraindications to surgery, or failed previous surgical intervention 6

Medical Management

Medical management of PHPT may include:

• Optimization of calcium and vitamin D intake 6
• Antiresorptive therapy for skeletal protection in patients with an increased fracture risk 6
• The use of cinacalcet, a calcimimetic agent, to lower serum calcium and PTH levels 6