Preliminary experience with cinacalcet use in persistent secondary hyperparathyroidism after kidney transplantation

Abstract

Background: There is limited experience with the use of cinacalcet in the treatment of persistent secondary hyperparathyroidism after kidney transplantation.

Methods: We retrospectively analyzed our experience in 18 renal allograft recipients who initiated cinacalcet therapy from 1 month to 23 years (median 3 years) posttransplantation and were maintained on the drug for 6 months. The daily dose was titrated from 30 mg up to a maximum of 180 mg to achieve a reduction in serum intact parathyroid hormone (PTH) levels.

Results: Sustainable, significant decreases in mean calcium and alkaline phosphatase were noted at 1 month and intact PTH by 3 months, with 50% of patients achieving at least a 30% drop in PTH levels at 6 months. Serum phosphorous increased at 6 months, whereas urine N-telopeptides decreased. There were no significant changes in serum osteocalcin, albumin, and hemoglobin levels. We did not observe a tachyphylaxis phenomenon. Two patients reported occasional nausea, but did not require medication discontinuation. Estimated glomerular filtration rate did decrease progressively over the 6-month period.

Conclusion: Cinacalcet appears to be an effective drug for the treatment of posttransplant hypercalcemia due to persistent secondary hyperparathyroidism. Further studies with more patients and longer follow-up will be needed to better elucidate the efficacy/safety profile for this agent, particularly with regard to long-term bone histology and renal outcomes.