Cinacalcet is effective in controlling the biochemical abnormalities in patients with
primary hyperparathyroidism (PHPT) but it seems to be less effective on bone mineral density (BMD). In the same patients,
bisphosphonates are reported to be effective on
bone resorption but less effective on
calcium and PTH excess. In this study, the efficacy of
cinacalcet in combination with
alendronate has been retrospectively evaluated in patients with PHPT. Twenty-three patients with PHPT who had not been operated were retrospectively investigated.
Cinacalcet was evaluated in combination with
alendronate in 10 of the 23 patients, and in monotherapy in 13 other patients. Serum
calcium,
phosphorus and PTH, 24 h urine
calcium and
phosphorus as well as BMD, evaluated by DXA and expressed as T-score, were measured before and
after treatment. In all patients serum
calcium and
phosphorus and urinary
calcium excretion were effectively and stably controlled and PTH was significantly decreased
after treatment. There was no difference in the rate of serum
calcium and PTH decrease between subjects treated with
cinacalcet plus
alendronate and those treated with
cinacalcet alone. T-score increased by 9.6% at lumbar spine and 3.9% at femur level in the
cinacalcet plus
alendronate subgroup and was unchanged in the
cinacalcet subgroup (P < 0.01). In patients with PHPT, the biochemical abnormalities are rapidly improved by
cinacalcet regardless from the administration in monotherapy or in combination with
alendronate. BMD is significantly improved in patients receiving
cinacalcet plus
alendronate and stable in those receiving
cinacalcet in monotherapy.