Corticosteroids — Clinical Use & Administration
Corticosteroids mimic a hormone you already make — but the difference between replacement dosing and pharmacologic dosing changes everything about why you're giving them and what to expect.
Core Concept
Corticosteroids (prednisone, hydrocortisone, methylprednisolone, dexamethasone) are synthetic versions of cortisol produced by the adrenal cortex. Their mechanism is suppression of the inflammatory and immune cascade — they induce lipocortin (annexin A1), which inhibits phospholipase A2, shutting down prostaglandin and leukotriene production upstream of where NSAIDs act. This makes them far more potent anti-inflammatory agents. Indications split into two categories: physiologic replacement (Addison's disease, adrenal insufficiency after surgery) and pharmacologic suppression (asthma exacerbations, autoimmune flares, organ transplant rejection, allergic reactions, cerebral edema). Administration timing matters — give oral doses in the morning to mimic the body's natural cortisol peak (6–8 AM), which minimizes HPA axis suppression. Doses taken with food reduce GI irritation. For acute situations, IV methylprednisolone provides rapid onset. Dose tapering is mandatory after use exceeding 1–2 weeks because exogenous steroids suppress the hypothalamic-pituitary-adrenal axis; abrupt withdrawal can trigger life-threatening adrenal crisis. Potency varies: dexamethasone has roughly 25 times the anti-inflammatory potency of hydrocortisone with no mineralocorticoid effect, making drug selection indication-specific.
Watch Out For
Don't confuse replacement therapy (low physiologic doses for adrenal insufficiency) with immunosuppressive therapy (high pharmacologic doses for inflammation) — indications and risk profiles differ significantly. Students mix up corticosteroids with anabolic steroids; corticosteroids cause muscle wasting, not building. Prednisone is a prodrug converted to prednisolone in the liver — impaired liver function may require prescribing prednisolone directly.
Clinical Pearl
Morning dose, with food, never stop cold turkey. Think of the adrenal glands as employees — if steroids do their job too long, the glands stop showing up to work.
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