Suppression of the hypothalamic-pituitary-adrenal axis and other systemic effects of inhaled corticosteroids in asthma

Inhaled corticosteroids have been available for the treatment of asthma for more than 20 years and are considered a primary modality in the prevention of hospitalization and reduction of inflammation, Although it is commonly thought that inhaled corticosteroids can be used at high doses for long periods of time with impunity, recent data suggest that side effects may be more common than previously appreciated, Although iatrogenic Cushing's syndrome and subsequent secondary adrenal insufficiency are rare, modest suppression of the hypothalamic pituitary adrenal axis is a common finding and is indicative of significant systemic absorption. Markers of bone formation and bone mineral density may be decreased, although not all studies have confirmed this finding. Although decreased growth velocity in children has been reported, final adult height does not seem to be less than expected with inhaled corticosteroids, Finally, an increase in the incidence of glaucoma and cataracts in older patients may be a real risk of long-term inhaled corticosteroid therapy, In conclusion, although inhaled corticosteroids clearly are preferable to oral steroid therapy for the treatment of asthma, significant systemic effects can occur.