Cure O asked:
Is it documented anywhere exactly what action of the steroids fail in the long term?
Hate to repeat myself, but I still dont understand what stops working with steroids after long term usage?
I don’t know exactly what actions of the steroids fail over time and hence don’t know the answer to your question. But, based on what I’ve read about the stress hormone cortisol, I’ll offer some speculation not about what fails in steroids over time, but what may fail in people with MS over time, i.e., people with MS may have defective glucocorticoid receptors and prolonged steroid use may exaggerate that problem and render steroids ever more ineffective and potentially damaging over time. Some abstracts……
This first one is a theory about MS but I think it speaks to the topic.The Role of Stress-Response Systems for the Pathogenesis and Progression of MS
Insensitivity to glucocorticoid and beta-adrenergic modulation might be involved in overshooting inflammation in MS, whereas hyperactivity of the HPA axis has been linked to neurodegeneration and increased disability.
Earlier research notes that corticosteroid resistance increases over time.Corticosteroid Resistance in a Population of MS Patients
found a trend towards worsening of clinical status over time with increasing corticosteroid resistance. These data suggest that corticosteroid sensitivity may be a factor in the pathogenesis and could be used for prognosis of MS.
And Lynda Carol recently alerted us to this:Irreversible Neurological Worsening Following High Dose Corticosteroids in Advanced Progressive MS
CONCLUSION: The use of high-dose corticosteroid therapy in progressive forms of MS outside relapses can be detrimental and worsen disability.
Again, I don’t know if defective and/or insensitive glucocorticoid receptors in people with MS are why steroids tend to become ineffective over time, but there seems to be a body of research that could at least lend some support to that idea. I do think there’s been some research that found defective glucocorticoid receptors on autopsy in people with MS.
Hope this helps a little bit, even if it doesn't directly answer your question.