Recovery of the hypothalamic-pituitary-adrenal axis from suppression by short-term, high-dose intravenous prednisolone therapy in patients with MS.

We have studied the recovery of the hypothalamic-pituitary-adrenal (HPA) axis from inhibition by short-term, intravenous high-dose, corticosteroid therapy (IVHDCT) without subsequent oral replacement therapy in 10 patients with relapsing-remitting or progressive multiple sclerosis (MS) using the human corticotrophin-releasing hormone (hCRH) test. There was significant HPA suppression with profoundly decreased basal and peak plasma ACTH and cortisol levels 24 h after cessation of therapy. However, at 48 h the pituitary response was greatly enhanced with peak ACTH concentrations rising by more than 100% over baseline values in 7 of 10 patients. Basal and stimulated ACTH concentrations returned to pre-treatment levels at 120 h. Basal and stimulated plasma cortisol levels remained subnormal in 6 patients 120 h after IVHDCT. We conclude that IVHDCT without oral replacement therapy in MS patients is endocrinologically safe.