Adrenal suppression following extradural steroids.

Adrenocortical function was tested in 12 patients following a single lumbar extradural injection of methylprednisolone acetate ('Depo-Medrol') 80 mg as treatment for chronic sciatica. There was no absorption of the corticosteroid into the systemic circulation, but marked suppression of plasma cortisol levels was documented for up to 3 weeks following the injection and the capacity of the adrenal cortex to secrete cortisol in response to synthetic adrenocorticotrophin (ACTH) was diminished. These results suggest that the dose and frequency of extradural steroid administration should be kept to a minimum to prevent suppression of the hypothalamic/pituitary/adrenocortical axis and that patients thus treated should be considered candidates for steroid cover during surgery and other stressful procedures.