Comparison of the effects of calcitriol and maxacalcitol on secondary hyperparathyroidism in patients on chronic haemodialysis: a randomized prospective multicentre trial.
BACKGROUND
To identify differences between the effects of calcitriol and the calcitriol analogue, maxacalcitol, on parathyroid hormone (PTH) and bone metabolisms, we conducted a randomized prospective multicentre study on patients on chronic haemodialysis.


METHODS
We randomly assigned 91 patients with secondary hyperparathyroidism [intact PTH (iPTH) > or =150 pg/ml] to have either calcitriol (47 patients) or maxacalcitol (44 patients) therapy, for 12 months after a 1 month control period. Serum electrolytes, bone alkaline phosphatase (bAP), iPTH, total PTH and PTH(1-84) (whole PTH) levels were measured periodically. The first end point was a serum iPTH of <150 pg/ml, the second was the iPTH levels obtained.


RESULTS
Treatment was discontinued for various reasons in nine patients in each group, but no serious side effects were observed in either group. The numbers of cases reaching the first end point were not significantly different between the two groups. Serum calcium concentration was significantly higher in the maxacalcitol than the calcitriol group during early treatment, but not at the end of treatment. Throughout the treatment period there were no significant differences between the two groups in serum iPTH, inorganic phosphate, the product of the serum calcium and inorganic phosphorus concentrations, bAP, or the ratio of whole PTH to total PTH minus whole PTH. Nor were the changes in these parameters significantly different between the two groups comparing the patients with moderate to severe hyperparathyroidism (basal iPTH > or =500 pg/ml).


CONCLUSIONS
Calcitriol and maxacalcitol are equally effective on PTH and bone metabolism.
Hayashi
Matsuhiko
M
Department of Internal Medicine, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan. matuhiko@sc.itc.keio.ac.jp
Tsuchiya
Yoshitsugu
Y
Itaya
Yoshiaki
Y
Takenaka
Tsuneo
T
Kobayashi
Kenji
K
Yoshizawa
Mamoru
M
Nakamura
Ryuichi
R
Monkawa
Toshiaki
T
Ichihara
Atsuhiro
A
D000469:Alkaline Phosphatase / Q000378:metabolism; D001842:Bone and Bones / Q000187:drug effects* / Q000378:metabolism; D002117:Calcitriol / Q000031:analogs & derivatives / Q000494:pharmacology / Q000627:therapeutic use*; D002118:Calcium / Q000097:blood; D002120:Calcium Channel Agonists / Q000494:pharmacology / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000097:blood / Q000188:drug therapy* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D010758:Phosphorus / Q000097:blood; D011446:Prospective Studies; D006435:Renal Dialysis
D002120:Calcium Channel Agonists; D010281:Parathyroid Hormone; D010758:Phosphorus; D000469:Alkaline Phosphatase; D002117:Calcitriol; C051883:maxacalcitol; D002118:Calcium