Endocrine Abstracts

Introduction: Cinacalcet is an effective treatment for primary hyperparathyroidism (PHPT). NICE recommends cinacalcet if calcium≥3.0mmol/l or ≥2.85 with symptoms, especially when surgery is not an immediate option. The aim of this study was to assess the utility, efficacy and impact of cinacalcet on the overall management of PHPT.

Methods: Data on all patients who were initiated on cinacalcet was collected. Data on indication for cinacalcet, baseline calcium, lowest calcium reached, hospital admissions for hypercalcaemia before and after initiation were analysed.

Results: n =121 Mean age: 72 years (25-97), 77% females. Mean calcium at initiation: 2.97mmol/l (2.66-3.58); PTH 18.4 pmol/l (2.5-107) Mean duration of follow up: 26 months (2-111). Mean average dose of cinacalcet: 42 mg/day (0-270) [9 patients discontinued due to intolerance] Indications for treatment were:

• Ca ≥3.0mmol/l = 53 (44%) • Ca ≥2.85 with symptoms=22 (18% based on NICE criteria). • Ca ≥2.85 with end organ damage=14 and failed surgery=2 (13% in total); • Other indications: Ca ≥2.85, asymptomatic and without end organ damage=16; Ca <2.85 and symptomatic =5; Ca <2.85 and asymptomatic =8; others =1 Mean number of hospital admission for hypercalcaemia reduced from 0.83 before cinacalcet to 0.51/patient. 33 patients reached lowest calcium between 2.2-2.4mmol/l with 3 developing biochemical hypocalcaemia during treatment. 31 patients still had Ca >2.6 at final review, with 27 had Ca <2.85 therefore less likely to be symptomatic.

Conclusion: Cinacalcet is an effective treatment for PHPT with substantial reduction in hospital admissions for severe hypercalcaemia. 75% of patients were treated based on biochemical NICE criteria or surgical criteria. Though NICE does not propose a target calcium on treatment to achieve with cinacalcet, calcium of 2.4-2.6 may be adequate for symptomatic relief, therefore 25% of the patients could be on a lesser dose thereby helping with cost reduction.