Endocrine Abstracts

Introduction: Cinacalcet is an allosteric modulator of the calcium sensing receptor which lowers parathyroid hormone (PTH) secretion. However, it is expensive and there is limited evidence of benefit in reducing complications of primary hyperparathyroidism (PHPT). In 2019 the National Institute for Health and Care Excellence (NICE) guidelines suggested that cinacalcet could be considered in individuals with PHPT if surgery has been unsuccessful or is unsuitable and if adjCa²⁺ is ≥2.85mmol/l with symptoms or ≥3.0mmol/l without symptoms.

Aims: We sought to; i) compare local cinacalcet prescribing practice to NICE guidelines and ii) perform a cost analysis of cinacalcet prescribing.

Methods: We identified all individuals prescribed cinacalcet from 2015 to 2020 from our pharmacy prescribing database and undertook an electronic case note review after excluding those prescribed cinacalcet from the renal clinic. Those starting cinacalcet prior to 2011 were excluded due to incomplete electronic records.

Results: 19 patients (6 male, 13 female) were identified that were prescribed cinacalcet from the endocrinology clinic between 2015 and 2020. All had PHPT. Cinacalcet was used as bridging therapy to surgery in 3 patients, with the remainder not suitable for surgery; indeed 5 patients were deceased at the time of audit. Mean age at initiation was 72 years with a mean starting adjCa² of 2.91mmol/l. The mean duration of treatment was 3.3 years and mean treatment dose was 64 mg/day (range 15-240 mg/day). 36.8% (7/19) became hypocalcaemic and 47.4% (9/19) achieved an adjCa²⁺ in the lower half of the local reference range (i.e. <2.41mmol/l) suggesting possible overtreatment. Only 52.6% (10/19) of these patients met 2019 NICE criteria, with a potential cost saving of £31,133.59 over 5 years.

Discussion: This audit highlights the importance of analysing local prescribing trends and ensuring compliance with national guidelines which could lead to significant cost savings and reduced side effects such as hypocalcaemia.