[How to manage the interruption of a treatment with anti-inflammatory corticosteroids?]

A prolonged treatment with anti-inflammatory corticosteroids induces an inhibition of ACTH secretion from pituitary corticotroph cells. An abrupt interruption of such a treatment potentially leads to the risk of an acute adrenal failure, in particular in stressing situations. The inertia in reactivation of the secretion of the stimulating hypothalamic factors (CRH and AVP) and consecutively of ACTH can be responsible for an inability to adapt the secretion of glucocorticoids in response to stress. A short-time treatment (<3 weeks) with anti-inflammatory corticoids does not expose to this risk. On the contrary, a more prolonged treatment, especially with high daily doses, needs to perform an evaluation of the level of corticotroph secretion. This evaluation should be done before to consider that either stopping the treatment is out of risk or if the initiation of a substitutive treatment with hydrocortisone is required. The measurement of morning plasma cortisol level already provides a significant information. As to whether that is needed, a dynamic evaluation can be performed. Among the available tests, the Synacthen(®)test, easy to perform and using at best 1μg of β1-24 ACTH, appears the most finely informative to answer this question and to choose the most adapted follow-up.