Comparison of Two Forms of Hydrocortisone in Patients With Congenital Adrenal Hyperplasia

This study will test a new, extended release form of hydrocortisone called Chronocort in patients with congenital adrenal hyperplasia (CAH). People with CAH do not make enough of the adrenal hormones cortisol and aldosterone, and their adrenal glands make too much of the sex hormone androgen. Medicines called glucocorticoids (hydrocortisone, dexamethasone and prednisone) are currently used to treat CAH, but finding the best dose of these drugs that effectively lowers androgens without causing undesirable side effects, such as weight gain and slow growth rate in children, is often difficult to achieve. Adolescents and adults with CAH due to 21-hydroxylase deficiency may be eligible for this study. Children 16 years of age and older are eligible with confirmation by bone age that they are no longer growing. Participants undergo the following tests and procedures during two inpatient visits one month apart at the NIH Clinical Center: * Medical history and physical examination. * Medications: Following 7 days of Cortef (standard drug treatment for CAH), patients begin taking Chronocort on day 3 of hospitalization and continue the tablets once a day for 1 month. * Blood tests: A catheter (plastic tube) is inserted in a vein and left in place for frequent blood draws in order to avoid repeated needlesticks. Blood is drawn for chemistries, blood count, pregnancy test in women, and for serial tests (up to 26 samples in a 24-hour period) to measure hormone levels. * 24-hour urine test. * Height and weight measurements. Between the two hospitalizations, patients are contacted by NIH weekly to check for possible side effects from Chronocort. Two weeks after the first visit, patients also will have blood drawn by their regular doctor or a local clinic. A few days before the second hospitalization, patients undergo a 20-minute telephone questionnaire about energy level and well being. About 30 days after discharge from the second hospitalization, patients are followed up with a telephone call to see how they are doing.

Congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency is a disease of the adrenal cortex characterized by cortisol deficiency with or without aldosterone deficiency, and androgen excess. The severe or classic form occurs in 1 in 15,000 births worldwide, while the mild non-classic form is a common cause of hyperandrogenism. The discovery of glucocorticoid therapy as a treatment for CAH occurred in the 1950's resulting in patients with classic CAH surviving to live a normal lifespan. However, existing treatment is suboptimal and many unresolved clinical problems exist. Standard hormone replacement often fails to normalize the growth and development of children with CAH, and adults may experience iatrogenic Cushing syndrome, hyperandrogenism, infertility or the development of the metabolic syndrome. Chronocort, a newly-developed formulation of hydrocortisone, results in a slow release of hydrocortisone that is designed to mimic the normal cortisol circadian rhythm. This new medical strategy, physiologic cortisol replacement, offers the prospect of an improved outcome of treatment. Chronocort has been safely given to healthy adult males in pharmacokinetic studies. This first ever study in patients with CAH is a pharmacokinetic/pharmacodynamic study comparing Chronocort to Cortef, the conventional immediate-release form of hydrocortisone.