Corticoids

Corticoids, or corticosteroids, are a class of steroid hormones produced by the adrenal cortex. The principal endogenous corticoids are glucocorticoids, led by cortisol, and mineralocorticoids, led by aldosterone. The term also applies to synthetic corticosteroids used as medicines. Glucocorticoids influence metabolism and the stress response, while mineralocorticoids regulate electrolyte and fluid balance.

In physiology, glucocorticoids promote glucose production and mobilization, affect fat and protein metabolism, and modulate the immune system and inflammatory processes. Mineralocorticoids act mainly on the kidneys to increase sodium reabsorption, promote potassium excretion, and help maintain blood pressure and extracellular fluid volume. Corticoids also interact with other hormonal axes, including the hypothalamic-pituitary-adrenal axis, which regulates their production in a circadian and stress-responsive manner.

Mechanistically, corticoids exert their effects by binding to intracellular receptors: the glucocorticoid receptor (GR) or the mineralocorticoid receptor (MR). Receptor activation alters gene transcription and cellular signaling, producing anti-inflammatory and immunosuppressive effects, among other actions. Long-term exposure can cause catabolic effects on bone, muscle, and skin and may affect mood and metabolism.

Medically, synthetic corticosteroids are widely used to treat inflammatory and autoimmune conditions, allergies, and certain cancers. Examples include prednisone, prednisolone, methylprednisolone, and dexamethasone, administered systemically or via inhaled, topical, or local routes. Fludrocortisone is a corticosteroid with predominant mineralocorticoid activity, used for mineralocorticoid replacement.

Adverse effects are dose- and duration-dependent and include hyperglycemia, osteoporosis, hypertension, infection risk, weight gain, and suppression of the hypothalamic-pituitary-adrenal axis. Careful dosing and tapering are important to minimize risks and avoid adrenal insufficiency on withdrawal.