Although daily dosing of cinacalcet may be an optimal treatment for secondary hyperparathyroidism (SHPT) compared with other dosing regimens, thrice-weekly post-dialysis dosing may be a viable option when daily dosing is ineffective because of patient noncompliance or other factors, a study suggests.
It is well established that cinacalcet provides optimal medical control of SHPT in patients who fail vitamin D or analogue therapy and who cannot undergo parathyroidectomy.
However, non-compliance can be a significant problem. Researchers at Tawam Hospital, United Arab Emirates, studied 23 chronic hemodialysis patients with refractory SHPT. Following a two-week run-in phase, the researchers randomly assigned patients to one of two groups. Group A patients received thrice-weekly post-dialysis dosing of cinacalcet and group B patients received daily home administration.
All subjects were maintained on calcitriol 0.5 mcg IV three times a week titrated along with cinacalcet to achieve control of SHPT up to a pre-assigned maximum dose of 240 mg for group A and 180 mg for group B.
Cinacalcet was well tolerated, with an average dose of 120 mg (range 30-150) three times a week in group A (12 patients) and 62 mg (30-120) daily in group B (11 patients). At 16 weeks, intact parathyroid hormone had declined significantly in group B but not in group A. A subgroup analysis showed that the greater effectiveness of dialysis dosing was seen in patients with less severe disease.
“Noncompliance is a widespread problem,” said investigator Ahmad Mohamed Chaaban, MD, a consultant nephrologist, who presented the study’s findings. “It looks like this approach of using thrice weekly dosing may be promising for patients with less serious disease and it may be effective at lowering secondary hyperparathyroidism.”