Endocrine Abstracts

Aim: Cinacalcet is a useful treatment option in primary hyperparathyroidism (PHPT) who are managed conservatively; however there are licensing issues and challenges for prescribing in primary care. The aim of our study was to assess the efficacy of cinacalcet treatment in PHPT and benefit of admission avoidance.

Methods: Data on patients treated with cinacalcet for PHPT were analysed. PTH, adjusted calcium and vitamin D at initiation, calcium at 6 and 12 months (if completed) and latest calcium were collected. Number of hospital admission for treatment of hypercalcaemia prior to (since 2012) and since cinacalcet initiation was collected.

Results: Of the 14 patients included in the study, 2 were men; Baseline parameters were (range in brackets): age 81.6 years (59–93), initial calcium 3.1 mmol/L (2.92–3.2), PTH 21.1 pmol/L (7.7–58.1), vitamin D 74 nmol/L (21.4–152.9, two patients were vitamin D deficient). Mean duration of treatment was 22 months (2–69). Latest calcium results were significantly better at 2.61 mmol/L (2.23–2.92, P<0.0001) with all patients showing an improvement from the initial calcium. Among patients who completed 6 months of treatment (n=12), calcium improved from 3.05 to 2.63 (P<0.0001), which was sustained at 12 months (n=8) with calcium improving from 3.02 to 2.52 P<0.005). Total number of hospital admissions for symptomatic hypercalcaemia (IV fluids or pamidronate infusion) reduced from 15 patient episodes (10 patients, mean 1.1 admission/patient, range 0–3) to 2 episodes (2 patients, mean 0.2 admission/patient, range 0–1), P=0.001. One patient developed biochemical hypocalcaemia during follow-up requiring dose alteration.

Conclusion: Our study demonstrates the immediate and sustained clinical efficacy of cinacalcet in PHPT. Cinacalcet can reduce the need for hospital/endocrine day case admissions for fluids and bisphosphonate infusions therefore providing a cost effective and safe treatment option for inoperable PHPT. Guidelines are required for continuation of this treatment in primary care.