Lack of benefit of clonidine treatment for short stature in a double-blind, placebo-controlled trial.

Twelve short (more than two standard deviations below the mean height for age), prepubertal children (ten boys, two girls) who had a normal peak growth hormone (GH) response to provocative stimulation with clonidine (more than 10 ng/ml) were enrolled in a double-blind, placebo-controlled, crossover study of the effects of a single, nightly dose of clonidine (0.1 mg/m2 by mouth). The children's mean age was 7.2 years (range 3.6-10.5 years). The results of 6 months of clonidine therapy were compared with those of 6 months of placebo. Clonidine therapy resulted in no significant difference in height standard deviation score, growth velocity, bone age, 24 h integrated GH concentration, peak GH response to clonidine stimulation, levels of insulin-like growth factor 1, or predicted height by the RWT method. In contrast to other studies, this study shows no sustained increases in GH production or in improved growth velocity with long-term administration of a single daily dose of clonidine. Furthermore, this study demonstrates the need for well-designed, placebo-controlled trials in paediatrics.