Comparison of dose frequency of human growth hormone in treatment of organic and idiopathic hypopituitarism.

Two weekly (biw) injections of pituitary human growth hormone (hGH) were compared with three weekly (tiw) injections of hGH (0.24 IU hGH/kg body weight/wk for both groups) for effect on growth rate in children with idiopathic and organic hypopituitarism. Both dosage schedules resulted in increased growth rate during the first 12 months of therapy; the tiw dosage was more effective in the first 6 months in patients with organic hypopituitarism, and in the second 6 months in patients with idiopathic hypopituitarism. There was no advantage to tiw therapy during the second year of therapy in either group. The additional increment in height after 1 year of therapy using tiw compared with biw therapy was 2 cm and 1 cm for the patients with organic and idiopathic hypopituitarism, respectively. This increment should be weighed against the cost, pain, and inconvenience of tiw versus biw doses of hGH in the treatment of hGH deficiency. With the dosages used in this study, tiw therapy was more effective during the first year, when patients are more responsive, and should be recommended. Twice weekly therapy could be considered for the second and possibly subsequent years of therapy. Other schedules of treatment may be more effective than either of these schedules.