Active vitamin D analogs, maxacalcitol and alfacalcidol, as maintenance therapy for mild secondary hyperparathyroidism in hemodialysis patients - a randomized study.

Background: The present randomized study was designed to compare the efficacy between two active vitamin D analogs, alfacalcidol (ACD) and maxacalcitol (OCT), for the management of mild secondary hyperparathyroidism (SHPT) in dialysis patients.

Methods: SHPT in all 32 patients analyzed in the study was initially treated with OCT. Once patients' intact PTH levels decreased to the target range of 150 - 180 pg/mL, they were randomized either to switch to ACD at 0.5 μg/day (n = 14), or to remain on an effectively unchanged dose of OCT (n = 13). Phosphate, calcium, and intact PTH levels were measured every 2 weeks for 12 weeks and vitamin D doses were changed according to target ranges of phosphate (3.5 - 6.0 mg/dL), calcium (albuminadjusted calcium: 8.4 - 10.0 mg/dL), and intact parathyroid hormone (60 - 180 pg/mL). Achievement rates of the target ranges of the parameters were estimated.

Results: Baseline calcium levels in the OCT group were significantly higher than in the ACD group. Changes in achievement rates of target ranges of intact PTH and calcium during the study did not differ significantly between the vitamin D drugs. Changes in calcium levels in the OCT and ACD groups were similar during the study. Achievement rates of the target range of phosphate in both groups were also similar until 8 weeks, although the rate in the OCT group declined at 10 weeks.

Conclusions: The efficacy and safety of OCT for the treatment of mild SHPT are similar to those of ACD in hemodialysis patients.