Endocrine Abstracts

A 72-year-old gentleman was diagnosed with primary hyperparathyroidism in 2005. He had 6 admissions in a year with hypercalcaemia refractory to treatment with conventional agents. On each admission he was treated with intravenous pamidronate and fluid resuscitation. This resulted in an average stay of 16 days and an average cost of £4800 per admission.

A single parathyroid adenoma was diagnosed on sestambiscan. He was not considered fit for surgery due to his co-morbidities (hypertension, type 2 diabetes, CVA, dementia). It was decided to commence the patient on Cinacalcet 30 mg once daily, which costs approximately £1646 per year. On Cinacalcet, the serum calcium levels have been well controlled without enduring any side effects.

Cinacalcet is an oral calcimimetic, which acts by increasing the sensitivity of calcium receptors in the parathyroid gland, thus reducing the levels of PTH. It is currently licensed for the treatment of refractory secondary hyperparathyroidism in patients with end-stage renal failure on maintenance dialysis therapy, and for parathyroid carcinoma in whom surgical parathyroidectomy is contraindicated. Response to treatment should be monitored regularly and treatment should only be continued if PTH levels are reduced by at least 30% within 4 months. Three key phase trials investigating the use of Cinacalcet in end-stage renal failure have reported that 43% of patients achieved a primary endpoint of a mean PTH level <250 pg/ml compared to 5% on placebo. Several unpublished trials investigating the use of Cinacalcet for primary hyperparathyroidism have shown Cinacalcet to be more effective than placebo in reducing calcium levels to within normal range, with concurrent significant reductions of PTH.