Effects of budesonide inhalation suspension on hypothalamic-pituitary-adrenal-axis function in infants and young children with persistent asthma

Background: The initial 12-week, double-blind phases of three studies demonstrated that budesonide inhalation suspension (BIS) is effective and well tolerated in infants and young children (6 months to 8 years of age) with persistent asthma. Objective: Open-label, 52-week extensions to these studies were conducted to evaluate long-term safety of BIS, including effects of treatment with the lowest effective dose of BIS on hypothalamic-pituitary-adrenal (HPA)-axis function, as compared with conventional asthma therapy (CAT). Complete results of the earlier phases of the studies and of long-term safety are reported elsewhere; only results pertaining to HPA-axis function are summarized here. Methods: Patients eligible for the open-label phases of the three trials were randomized to treatment with nebulized BIS (n = 447) or CAT (n = 223). CAT included short-acting oral or inhaled beta(2)-agonists, methylxanthines, or cromolyn sodium; in two of the studies, CAT could have included other inhaled corticosteroids. HPA-axis function, which had been evaluated during the 12-week double-blind studies, was again evaluated at the beginning and end of the 52-week study period using basal plasma cortisol concentrations and response to stimulation with a 250-mug dose of adrenocorticotropic hormone. Results: There was no evidence of altered HPA-axis function attributable to BIS treatment. No clinically or statistically significant differences in basal or adrenocorticotropic hormone-stimulated plasma cortisol concentrations were observed between BIS and CAT in either the 12-week, double-blind or 52-week, open-label phases of the three studies. Conclusions: The results indicate that treatment with BIS does not result in clinically significant suppression of HPA-axis function in infants and young children.