Oral clonidine-an effective growth hormone-releasing agent in prepubertal subjects.

The effects of clonidine, metoclopramide, and insulin on growth hormone, cortisol, and glucose concentrations in the blood of 17 healthy prepubertal short children (Group A) and five prepubertal growth hormone-deficient children (Group B) were evaluated. The peak serum growth hormone values after insulin and clonidine were significantly higher than after metoclopramide administration. Growth hormone values did not rise above baseline values in Group B patients with any of these three stimuli. Plasma cortisol concentrations did not change with metoclopramide but increased significantly with insulin and decreased significantly after clonidine; no changes in glucose values were noted with either clonidine or metoclopramide. Clonidine appears to be a reliable, sensitive, and safe out-patient stimulation test of growth hormone reserve in prepubertal children, whereas metoclopramide seems not to be a suitable growth hormone-releasing agent in this age group.