Cinacalcet reduces serum calcium concentrations in patients with intractable primary hyperparathyroidism. The Journal of clinical endocrinology and metabolism [J Clin Endocrinol Metab] Journal article

Context: Patients with persistent primary hyperparathyroidism (PHPT) after parathyroidectomy or with contraindications to parathyroidectomy often require chronic treatment for hypercalcemia.
Objective: To assess the ability of the calcimimetic, cinacalcet, to reduce serum calcium in patients with intractable PHPT.
Design: Open-label, single-arm study comprising a titration phase of variable duration (2-16 wk) and a maintenance phase of up to 136 wk.
Setting: Twenty-three centers in Europe, the United States, and Canada.
Patients: Seventeen patients with intractable PHPT and serum calcium > 12.5 mg/dl (3.1 mmol/liter). Intervention: During the titration phase cinacalcet dosages were titrated every 2 wk (30 mg twice daily to 90 mg four times daily) for 16 wk until serum calcium was </= 10 mg/dl (2.5 mmol/liter). If serum calcium increased during the maintenance phase, additional increases in the cinacalcet dose were permitted. Main Outcome Measure: The primary endpoint was the proportion of patients experiencing a reduction in serum calcium of >/= 1 mg/dl (0.25 mmol/liter) at the end of the titration phase.
Results: Mean +/- SD baseline serum calcium was 12.7 +/- 0.8 mg/dl (3.2 +/- 0.2 mmol/liter). At the end of titration, a >/= 1 mg/dl reduction in serum calcium was achieved in 15 patients (88%). Fifteen patients (88%) experienced treatment-related adverse events, none of which were serious. The most common adverse events were nausea, vomiting, and paresthesias.
Conclusions: In patients with intractable PHPT, cinacalcet reduces serum calcium, is generally well tolerated, and has the potential to fulfill an unmet medical need.

The Journal of clinical endocrinology and metabolism [J Clin Endocrinol Metab]