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 m²). 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.