CLINICAL RELEVANCE OF INHALED CORTICOSTEROIDS AND HPA AXIS SUPPRESSION

Although hypothalamic-pituitary-adrenal (HPA) asis suppression has tra ditionally been viewed as an adverse event after long-term administrat ion of corticosteroids, this effect can also be used to compare the po tency of different inhaled corticosteroids. However, various factors s uch as the dose, frequency of administration, treatment duration, stud y population (patients with asthma versus normal volunteers), and prio r systemic steroid therapy influence adrenal suppression with inhaled corticosteroids. The different adrenal function tests available and th e results produced with these tests also must be considered along with the clinical relevance of such results. Whereas low doses of inhaled corticosteroids are likely to cause minimal or no HPA asis suppression , longterm high-dose inhaled corticosteroid use may result in signific ant suppression by effectively replacing endogenous steroid production . The risk of acute adrenal insufficiency in patients taking low/mediu m-dose inhaled corticosteroids is minimal, but patients receiving long -term high-dose treatment may require supplementary systemic steroids during stress challenges, especially if they have previously received long-term systemic steroid treatment.