Adrenal Suppression Secondary to Interaction of Combined Inhaled Corticosteroid and Antifungal Agent

Abstract

Objective: Inhaled corticosteroids (ICS) are exogenous glucocorticoids that typically have minimal systemic effects at standard doses. They are metabolized by the cytochrome P450 (CYP450) enzyme pathway in the liver; thus, they can cause unwanted side effects when used in conjunction with medications affecting this system. Here, we present a case of adrenal suppression (AS) secondary to combined usage of ICS and posaconazole, a known CYP450 inhibitor. Methods: Clinical and laboratory data were isolated and are presented. Results: A 9-year-old Caucasian female with history of hyper IgE syndrome. On chronic fluticasone and posaconazole for Aspergillus infection, she presented with fatigue and “facial puffiness” (cushingoid features). Low morning cortisol (0.3 μg/dL) prompted further evaluation. Low-dose (1 μg) adrenocorticotropic hormone (ACTH)-stimulation test with peak cortisol level <1 μg/dL. Other causes of hypocortisolism were ruled out. Started on physiologic hydrocortisone (10 mg/m2/day) and fluticas...