Corticosteroids are hormones synthesized from cholesterol by the adrenal cortex and have a wide range of physiological functions. Pharmacologically they are divided according to the relative potencies of their pharmacological effects into; 1) Glucocorticoids that principally affect carbohydrate and protein metabolism (type II receptor) 2) Mineralocorticoids that principally affect sodium balance (type I receptor) Production of the naturally occurring glucocorticoid, cortisol (hydrocortisone), is stimulated by the release of adrenocorticotrophic hormone (ACTH) from the anterior pituitary. Production of the major naturally occurring mineralocorticoid, aldosterone is controlled by other factors in addition to ACTH, including the activity of the renin-angiotensin system and plasma potassium. Synthetic steroids have largely replaced the natural compounds in therapeutic use as they are usually more potent, may be more specific with regard to mineralocorticoid and glucocorticoid activity and can be given orally. Prednisone, betamethasone and dexamethasone are widely used as anti-inflammatory and immunosuppressant drugs. Corticosteroids are usually given for one of the following three reasons; 1) Suppression of inflammation 2) Suppression of immune response 3) Replacement therapy.