Treatment of adult patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency: a clinical practice audit.

OBJECTIVE

To review one physician's management of glucocorticoid replacement therapy in adult patients with congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency and to determine the efficacy and the range of effective doses of dexamethasone in managing the clinical and biochemical consequences of this disorder.

METHODS

We conducted a retrospective clinical practice audit of nine patients treated by a single physician for 21-hydroxylase deficiency during the period from March 1998 to January 2002. We documented biochemical control and clinical features of glucocorticoid excess or deficiency for various doses of dexamethasone.

RESULTS

The final dosage of dexamethasone needed to normalize serum 17-hydroxyprogesterone levels, to arrest progression of hirsutism, and to eliminate the symptoms and signs of adrenocortical insufficiency while avoiding manifestations of glucocorticoid excess ranged from 0.0625 to 0.875 mg/day, with a mean dosage of 0.4 mg/day. Seven patients had adequate control during the observation period with use of dosages of dexamethasone of 0.5 mg/day or less.

CONCLUSION

Adequate control of 21-hydroxylase can be achieved with relatively low doses of dexamethasone; thus, the long-held notion that 0.75 mg of dexamethasone is "equivalent" in glucocorticoid effect to the estimated daily production of cortisol is challenged. These data suggest that physicians should evaluate the doses of glucocorticoids used in their patients with CAH and other forms of primary and central adrenocortical insufficiency because considerable decreases in glucocorticoid doses may be in order.