Systemic Corticosteroid Therapy

Systemic corticosteroids are synthetic glucocorticoids used to rapidly suppress inflammation and immune activity. Prednisone, prednisolone, methylprednisolone, dexamethasone, and hydrocortisone are common examples. They may be used for acute asthma or COPD exacerbations, autoimmune disease flares, inflammatory bowel disease, transplant-related immunosuppression, cerebral edema, and selected critical illnesses. Glucocorticoids enter cells and bind cytoplasmic glucocorticoid receptors. The receptor-drug complex then changes gene transcription, reducing production of inflammatory mediators and dampening immune-cell activity. This broad action can be life-saving, but it also explains why the adverse effects are broad: glucose regulation, bone turnover, skin integrity, mood, infection response, and the hypothalamic-pituitary-adrenal (HPA) axis can all be affected. Endogenous cortisol is normally released under control of hypothalamic corticotropin-releasing hormone (CRH) and pituitary adrenocorticotropic hormone (ACTH). Exogenous glucocorticoids signal that the body already has sufficient cortisol. CRH and ACTH fall, and the adrenal cortex gradually reduces its own cortisol production. With sustained exposure, adrenal tissue atrophies. The clinical consequence is not simply “steroid dependence.” A patient may look well while taking prednisone yet be unable to produce adequate cortisol when the medication is reduced, stopped,...