Pharmacology: Pharmacodynamics: Hydrocortisone is a glucocorticoid secreted by the adrenal cortex. It decreases inflammation by suppression of migration of polymorphonuclear leukocytes and reversal of increased capillary permeability.
Pharmacokinetics: Hydrocortisone is readily absorbed from the GI tract. It is reversibly bound to corticosteroid binding globulin (CBG or transcortin) and corticosteroid binding albumin (CBA). Hydrocortisone is metabolized by the liver which is the rate-limiting step in its clearance. Induction of hepatic enzymes will increase the metabolic clearance of hydrocortisone. About 1% of its usual daily production, or about 200 mcg unchanged hormone is excreted in urine daily. Hydrocortisone is primarily excreted in urine as 17-hydroxysteroids and 17-ketosteroids. Renal clearance is increased when plasma levels are increased. Its half-life elimination is 8-12 hours.