[Cinacalcet in patients on peritoneal dialysis with moderate to severe hyperparathyroidism resistant to conventional treatment, a one-year, prospective study].
BACKGROUND
Cinacalcet has improved the management of hyperparathiroidism (HPTH) in hemodialysis. To our knowledge there are no specific studies on peritoneal dialysis (PD).


OBJECTIVE
The aim of the present study was to evaluate the efficacy of Cinacalcet on the achievement of optimal and suboptimal targets on treatment of hyperparathiroidism (HPTH) in PD patients. As secondary objectives we have studied the safety of treatment and estimate the mean time to reach these targets, and evaluate economic cost.


METHODS
Eighteen patients undergoing more than 4 months on PD with a severe HPTH (PTH > 500 pg/ml) resistant to conventional treatment with diet, chelants and vitamin D were included in this prospective open-label study. We have used the targets of K/DOQITM-clinical guidelines as optimal target. We have selected as suboptimal targets: PTH < 350 pg/ml, phosphorus < 6 mg/dl and calcium < 10.4 mg/dl (only when simultaneous CaxP was under 55 mg2/dl2). Oral Cinacalcet was given with main meal in a single daily start dose of 30 mg and titrated thereafter monthly. We considered the first value on target as an event and used a Kaplan-Meyer survival analysis to estimate mean time to reach target.


RESULTS
On inclusion all patients have at least two previous PTH values over 500 pg/ml, PTH mean 695,3 (SD 96) and they were on PD with an appropriate efficacy during a mean of 15.56 months (SD 0.78). Mean follow-up time under Cinacalcet treatment was 12 months. The percentage of patients with a PTH under 350 pg/ml was 66,7% on month 3, 60% on month 6 and 100% after 1 year. The percentage of patients that reach an aggregate of all suboptimal targets (PTH< 350 pg/ml and calcium < 10.4 mg/dl and phosphorus< 6 mg/dl and CaxP < 55 mg2/dl2) was 33.3% on month 6 and 66.7% after 1 year. The mean time to reach PTH target was 2.33 months with a 95% confident interval [1.35-3.32] and to reach the aggregate of all target was 16.94 months [11.38-22.5]. Cinacalcet has been well tolerated, we reduced the dose in a single patient due to secondary effects, but treatment was not discontinued in any case.


CONCLUSIONS
In summary the addition of Cinacalcet to conventional treatment in PD patients with resistant HPTH has improved the achievement of targets, and has been reasonably safe in our patients.
Portolés
J
J
Servicio de Nefrología, Hospital Universitario Fundación Alcorcón, Madrid, España. jmportoles@fhalcorcon.es
Tato
A
A
López-Sánchez
P
P
Gruss
E
E
Cava
F
F
Ortigosa
A
A
Molano
M D
MD
D000069449:Cinacalcet; D005260:Female; D006801:Humans; D006961:Hyperparathyroidism / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D009281:Naphthalenes / Q000627:therapeutic use*; D010530:Peritoneal Dialysis; D011446:Prospective Studies; D012720:Severity of Illness Index; D013997:Time Factors; D017211:Treatment Failure
D009281:Naphthalenes; D000069449:Cinacalcet