Treatment with Calcimimetic (Cinacalcet) Alters Epoetin Dosage Requirements in Dialysis Patients: Preliminary Report

Background: Secondary hyperparathyroidism (SHPT), known complication of chronic renal failure, in addition to effects on bone and cardiovascular systems, is associated with reduced response to erythropoietin (EPO). Calcimimetics such as cinacalcet are the latest generation of drugs used in the treatment of SHPT. Few studies have evaluated the effect of cinacalcet on anemia associated with SHPT in dialysis patients, while no study has compared this cinacalcet effect with that of vitamin D analogs such as paricalcitol. Patients and methods: Using a retrospective chart-based review of dialysis patients'' records to identify patients being treated with either cinacalcet or paricalcitol alone, matched for the same EPO treatment, which had been followed for 1 year, we have evaluated the effect of cinacalcet on anemia compared to that of paricalcitol. Results: Ten patient records were found that fit the criteria, five treated with cinacalcet (Group 1) and five treated with paricalcitol (Group 2), all treated with the same dose of darbepoetin. Darbepoetin dosage was the only parameter that significantly changed between groups, decreasing in Group 1 (--33%%, p == 0.009) while remaining unchanged in Group 2. PTH-level reduction, which was significant versus baseline in both groups, although not statistically different between groups, was higher with cinacalcet. Conclusion: The combination of lower EPO dose in cinacalcet-treated patients compared with paricalcitol-treated patients, along with good SHPT control is a novel information and might have considerable benefits in dialysis patients not only preventing bone (fractures) and cardiovascular system (calcifications) damages but also in terms of cost savings via a reduction of EPO dosage.