What is the diagnosis for an elderly woman with persistent hypercalcemia, ionized calcium level of 1.35 mmol/l, and elevated parathyroid hormone (PTH) level of 72.34 pg/ml?

From the Guidelines

This patient likely requires surgical parathyroidectomy due to severe hyperparathyroidism associated with hypercalcemia, as indicated by the elevated ionized calcium (1.35 mmol/l) and PTH level (72.34 pg/ml) 1. The patient's condition suggests primary hyperparathyroidism, which is typically characterized by an inappropriately normal-to-high PTH level in the presence of hypercalcemia.

• Key considerations in managing this patient include:
  • Referral to an endocrinologist and surgeon for evaluation for parathyroidectomy, which is the definitive treatment for primary hyperparathyroidism 1.
  • Maintaining adequate hydration, avoiding calcium supplements, and limiting dietary calcium intake while awaiting specialist evaluation.
  • Potential use of bisphosphonates like alendronate or cinacalcet (a calcimimetic) for temporary management of hypercalcemia if symptoms are severe or surgery is contraindicated.
• Monitoring should include regular calcium, phosphorus, vitamin D, and renal function tests to assess the patient's response to treatment and adjust the management plan as needed 1. The choice of surgical procedure, such as subtotal or total parathyroidectomy, with or without implantation of parathyroid tissue, may be at the discretion of the surgeons involved, as all methods can result in satisfactory outcomes 1.
• It is essential to consider the patient's overall health status and symptom burden when making treatment decisions, particularly in elderly patients who may be asymptomatic or present with subtle symptoms like fatigue, bone pain, cognitive changes, or kidney stones.

From the FDA Drug Label

Approximately 60% of patients with mild (iPTH ≥ 300 to ≤ 500 pg/mL), 41% with moderate (iPTH > 500 to 800 pg/mL), and 11% with severe (iPTH > 800 pg/mL) secondary HPT achieved a mean iPTH value of ≤ 250 pg/mL. Seventeen patients with severe hypercalcemia due to primary HPT, who had failed or had contraindications to parathyroidectomy, participated in an open-label, single-arm study. At baseline the mean (SE) serum calcium was 12.7 (0.2) mg/dL. At the end of the titration phase the mean (SE) serum calcium was 10.4 (0.3) mg/dL, which is a mean reduction of 2. 3 (0. 3) mg/dL from baseline.

The patient's ionized calcium level is 1.35 mmol/l and pth 72.34 pg/ml.

• The patient's PTH level is below the range of mild secondary HPT (iPTH ≥ 300 to ≤ 500 pg/mL) mentioned in the study.
• The patient's ionized calcium level is lower than the baseline serum calcium levels in the primary HPT studies (12.7 mg/dL or 3.18 mmol/L and 12.5 mg/dL or 3.12 mmol/L). Given the information provided, cinacalcet may not be the best option for this patient as the drug label does not provide direct evidence to support its use in patients with these specific characteristics 2.

From the Research

Patient Profile

• The patient is an old woman with persistent hypercalcemia, ionized calcium level of 1.35 mmol/l, and parathyroid hormone (PTH) level of 72.34 pg/ml.

Treatment Options

• Cinacalcet hydrochloride (Sensipar) is a potential treatment option for secondary hyperparathyroidism and hypercalcemia in patients with parathyroid carcinoma 3.
• Cinacalcet has been shown to be effective in reducing PTH, serum calcium, phosphorus, and calcium-phosphate product levels in clinical trials 3, 4.
• The combination of cinacalcet and vitamin D has been found to be more effective than vitamin D alone in lowering serum calcium, phosphorus, and calcium-phosphate product levels in patients with secondary hyperparathyroidism 4.

Safety and Efficacy

• Cinacalcet has been found to be generally safe and well-tolerated, with mild adverse effects 3, 5.
• The risk of hypocalcemia and nausea or vomiting is higher with the combination of cinacalcet and vitamin D compared to vitamin D alone 4.
• Cinacalcet has been shown to be effective in lowering serum calcium and PTH levels in patients with primary hyperparathyroidism, with a significant reduction in serum calcium levels and a decrease in PTH levels 6, 5.

Considerations

• The patient's PTH level is elevated, which may indicate primary hyperparathyroidism.
• Cinacalcet may be a potential treatment option for this patient, given its efficacy in lowering serum calcium and PTH levels in patients with primary hyperparathyroidism 6, 5.
• However, the patient's ionized calcium level is also elevated, which may require careful monitoring and adjustment of treatment.