To explore the potential effect of dose schedule on the adrenal suppressive action of hydrocortisone in congenital adrenal hyperplasia, eight patients (six with 21-hydroxylase deficiency and two with 11-hydroxylase deficiency) were given five different dose schedules. Two of the schedules used single daily doses (morning or evening), two twice daily doses (two-thirds dose in the morning or evening), one and three equal doses at morning, noon, and night. Each dose schedule used the same total daily hydrocortisone dose (12.5 mg/m2/day), which is within the normal range of hydrocortisone production rate. Each schedule was given for 4 to 6 weeks. The different dose schedules caused the predicted alterations in the temporal pattern of adrenal steroid levels, with the greatest apparent suppression during the 2 to 4 hours after each dose. None of the schedules, however, caused significant differences in the mean 24-hour plasma concentration of 17-hydroxyprogesterone (21-hydroxylase deficiency) or 11-deoxycortisol (11-hydroxylase deficiency) or in the 24-hour urine pregnanetriol or 17-ketosteroid concentrations, either in the six patients undertreated at the dose of 12.5 mg/m2/day or in the two patients adequately treated. Nocturnal administration of all or a part of the daily dose did not improve adrenal suppression. These observations suggest that treatment of congenital adrenal hyperplasia with a once-a-day hydrocortisone dose schedule may be as effective as conventional multiple-dose schedules. Until this hypothesis has been tested by more extended clinical studies, however, we do not recommend a once-a-day schedule. Regardless of the dose schedule, the total daily hydrocortisone dose must be adjusted to achieve a normal rate of growth and bone age advancement.
ASJC Scopus subject areas
- Pediatrics, Perinatology, and Child Health