Cinacalcet in the treatment of persistent hyperparathyroidism after kidney transplantation

Secondary hyperparathyroidism persists in 30 - 50% of patients after a successful kidney transplant and it is the most frequent cause of hypercalcemia after transplant, contributing to graft loss and mortality. Several medical therapies have been studied for the treatment of this condition without clear benefit. Recently, interest has grown in the use of cinacalcet in kidney transplant recipients.

We describe the efficacy of cinacalcet in 18 kidney transplant patients with persistent hyperparathyroidism and progressive hypercalcemia treated for a period of 12-months. We analyzed serum calcium, phosphorus and parathyroid hormone levels every 6 months, and cinacalcet was titrated if necessary. Statistical analysis was performed using ANOVA.

With therapy, all patients exhibited significant reduction in parathyroid hormone levels, from a mean value of 242.04 ± 105.82 pg/ml to a mean value of 145.62 ± 54.99 pg/ml (p < 0.001) 12 months later. In addition, serum calcium levels normalized during the study period, from 11.16 mg/d to 9.95 mg/dl (mean values) (p < 0.001). No significant change in serum creatinine was found in this group of patients. Cinacalcet was well tolerated, with no side effects documented.

This preliminary experience suggests that cinacalcet may be useful in the treatment of persistent hyperparathyroidism after kidney transplant. In addition, cinacalcet controlled hypercalcemia, which has well known adverse effects after transplant. This was accomplished with no evidence of declining kidney function or limiting side effects.