The Half-Life of Hydrocortisone in Normal Newborn Infants

The exact functional status of the adrenal cortex during the newborn period and the limits within which this gland functions during early life are not yet known. Although data are available concerning the urinary excretion of steroids by individual normal premature and term infants,^1,2 the correlation between the function of the adrenal cortex, blood levels of adrenal steroids, and tissue utilization and urinary excretion of these hormones remains obscure. It has been generally accepted that the biological half-life of administered hydrocortisone is an indicator of steroid metabolism and it has been shown that the half-life of hydrocortisone is altered in certain diseases, such as rheumatic fever, cirrhosis, and thyrotoxicosis.^3,4 The purpose of this communication is to report the results of hydrocortisone half-life studies which were performed on normal newborn infants.

Method and Materials  Thirteen hydrocortisone half-life determinations were done on 12 patients; 3 patients were "normal" premature infants,