The effect of cyproheptadine and human growth hormone on adrenocortical function in children with hypopituitarism.

The cortisol response to insulin hypoglycemia was determined in ten hypopituitary children treated for four months with both growth hormone and cyproheptadine, and in six other children with hypopituitarism treated for four months with hGH alone. All patients had previously normal responses to orally administered metyrapone. There was no demonstrable difference in the F responses to insulin hypoglycemia before and four months following its discontinuation in the patients receiving hGH alone. In the ten patients on combined therapy the F response to insulin hypoglycemia was normal in five and subnormal in five patients. These ten patients were retested at least two months after cessation of CPH therapy. The F response reverted to normal in four of the five patients in whom it had been subnormal. There was no significant change in the five patients with initial normal response. No patients had signs or symptoms of glucocorticoid insufficiency. In some cases, long-term administration of CPH to children with hypopituitarism is associated with decreased F response to insulin hypoglycemia; this may represent decreased adrenocortical reserve in these patients. The previously reported enhancement of growth of hypopituitary children treated with hGH and CPH may in part be a result of decreased F production.