Efficacy of low-dose cinacalcet on alternate days for the treatment of secondary hyperparathyroidism in hemodialysis patients: a single-center study

INTRODUCTION: Cinacalcet is effective in reducing serum parathyroid hormone (PTH) in patients with secondary hyperparathyroidism (HPT). This study focused on testing whether a prescription of low-dose cinacalcet on alternate days could be an option for treatment of secondary HPT. MATERIALS AND METHODS: A retrospective clinical study was conducted on chronic maintenance hemodialysis patients. Patients with secondary HPT who received cinacalcet at a starting dose of 25 mg on alternate days were reviewed (low-dose group). Patients who were being treated with a standard dose of cinacalcet in the same period of time were selected as the control group. The primary outcome was difference in the percentage of patients achieving >30% reduction of intact parathyroid hormone (iPTH) levels at 16 weeks. The changes of serum iPTH and other biochemical data were also tested. RESULTS: A total of 30 patients (16 low doses and 14 controls) took part in the study. Baseline iPTH levels in the low-dose and control group were 1,065.9±477.7 and 1,214.1±497.6 pg/mL, respectively (p=0.413). The analysis showed that the percentage of patients who achieved the primary outcome showed little or no difference (33.3% in the low-dose group compared with 38.5% in the control group, p=1.0). Serum iPTH reduction during 16 weeks of study period in the low-dose and control group was 253.5±316.1 and 243.4±561.3 pg/mL, respectively (p=0.957). There was no difference in the adverse events between both groups. CONCLUSION: Among patients with secondary HPT, initial treatment with cinacalcet 25 mg on alternate days can decrease serum PTH levels. The role of low-dose cinacalcet in secondary HPT should be further determined in large-scale, randomized controlled trials.