Of 58 patients (81% male), 67% were on FP (median age years [range -], dose 1320 μg/d [440-1760], treatment duration years [-]). Thirty-three percent were on budesonide (median age years [range -], dose 1000 μg/d [500-2000], treatment duration years [-]). The overall prevalence of abnormal peak cortisol response (≤ 20 μg/dL) was 15% (95% CI 6%-25%) (indeterminate [18-20 μg/dL] 5% [n = 3] vs AI [<18 μg/dL] 10% [n = 6]). All patients on budesonide had a normal response vs only 77% of patients on FP (P = .02), all of whom were taking FP at a dose >440 μg/d.
Glucocorticoids are potent anti-inflammatories, regardless of the inflammation's cause; their primary anti-inflammatory mechanism is lipocortin-1 (annexin-1) synthesis. Lipocortin-1 both suppresses phospholipase A2 , thereby blocking eicosanoid production, and inhibits various leukocyte inflammatory events ( epithelial adhesion , emigration , chemotaxis , phagocytosis , respiratory burst , etc.). In other words, glucocorticoids not only suppress immune response, but also inhibit the two main products of inflammation, prostaglandins and leukotrienes . They inhibit prostaglandin synthesis at the level of phospholipase A2 as well as at the level of cyclooxygenase /PGE isomerase (COX-1 and COX-2),  the latter effect being much like that of NSAIDs , potentiating the anti-inflammatory effect.