MON-474 Adrenal Control in Pediatric 11β-Hydroxylase Deficient CAH Patients Using Different Hydrocortisone Formulations: A Two-Patient Case Study

Abstract Disclosure: P. Seo: None. M.M. Rutter: None. M. Yau: None. The classical form of 11β-hydroxylase deficiency (11-β OHD) CAH is differentiated by severe hypertension due to the mineralocorticoid effect of deoxycorticosterone and hyperandrogenism. For children, the Endocrine Society recommends daily hydrocortisone (HC) at 10-15 mg/m^2/day in divided doses. As children grow, frequent biological and laboratory monitoring is needed for small-dose titrations of HC to optimize adrenal control. Oral HC tablets are not explicitly designed for children, necessitating splitting tablets or having pediatric-specific formulations compounded. This process makes it challenging to deliver consistent doses, particularly for amounts less than 5 mg. In late 2020, the US FDA approved a pediatric-specific HC formulation in oral granules, with doses as low as 0.5 mg. Objective To assess adrenal control in CAH on various formulations of HC, we retrospectively reviewed the medical records of two pediatric patients with 11-β OHD who had received different formulations of oral HC (solution, tablets, and oral granules) for up to 4.5 years. Methods We collected demographic, anthropometric, and pubertal data, laboratory results, and medication formulation and dosing over multiple time points during pediatric endocrine follow-up. Laboratory results included ACTH, androstenedione, plasma renin activity (PRA), deoxycorticosterone, and 11-deoxycortisol concentrations. Choice of HC oral formulations was based on family preference and provider recommendation. Results Patient 1 (27-53 mo) was initially prescribed HC solution at doses of 8.5 -14.3 mg/m^2/day and transitioned to granules at 41 mo at 11.7-14.6 mg/m^2/day. Adrenal control on HC solution and granules was similar on solution and granules with androstenedione of 31-56 ng/dl, PRA of 0.17-2.7 . ACTH peaked at 54.8 pg/mL at 38 mo But normalized over time. Androstenedione stayed within the normal range, while 11-deoxycortisol peaked at 232 ng/dL. PRA remained below normal, except at 41 mo. Patient 2 (5-39 mo) transitioned from HC solution at 18 mg/m^2/day to tablets at 16-19 mg/m^2/day at 9 mo and then to granules at 14 m.o. While on granules, HC doses decreased from 18.2 to 7.25 mg/m^2/day due to poor compliance. Until 30 mo, ACTH and androstenedione remained low, respectively at<6 pg/mL) and <10 ng/dL). PRA was consistently below the normal range, and 11-deoxycortisol spiked at 30 mo (2029 ng/dL) and androstenedione rose to 115 ng/dl at 39 mo. Changes in formulations were well tolerated. Conclusion The results indicate that adrenal control was influenced by factors beyond the formulation of HC. Variations in adrenal control were observed based on the dosage of HC relative to body surface area, with the total daily dose emerging as a primary determinant of adrenal regulation. Adherence with medication dosing and stressful blood draws may have contributed to poor adrenal control and should be explored further. Presentation: Monday, July 14, 2025