Growth in children with chronic renal failure on intermittent versus daily calcitriol

Calcitriol (C) treatment strategies for secondary hyperparathyroidism remain controversial regarding efficacy and safety. In children, intermittent C administration has been suspected of impairing body growth. In a prospective, randomized multicenter study, we compared the effect of daily versus twice weekly C on plasma intact parathyroid hormone (iPTH) levels and growth in 24 prepubertal children with chronic renal insufficiency (mean creatinine clearance 20+/-9 ml/min per 1.73 m(2)). After a 3-week washout period, the patients were randomly assigned to 10 ng/kg per day or 35 ng/kg twice a week oral C. The C dose was kept constant for 2 months and could then be adapted to maintain an iPTH target range of 140-280 pg/ml. Median (range) baseline iPTH levels were 567 (114-1209) pg/ml in the daily and 332 (93-614) pg/ml in the intermittent treatment group ( P=NS). After 12 months, iPTH had decreased to 255 (85-710) and 179 (51-443) pg/ml ( P<0.01). The average weekly dose of C was 76+/-34 and 62+/-34 ng/kg ( P=NS). Five episodes of calcium phosphate product>/=70 occurred in the daily group and four in the intermittent group. The change in height standard deviation score during the study period was not affected by either treatment modality (-0.18+/-0.34 vs. -0.05+/-0.52, P=NS). Daily and intermittent C do not differentially affect growth rate and are equally effective in controlling secondary hyperparathyroidism in children with chronic renal failure.