Glucocorticoid physiologic effects

The uses of corticosteroid antiinflammatory dmgs in veterinary medicine are many and varied. In the intact animal, the glucocorticoids and mineralcorticoids are produced in the adrenal glands. Exogenous compounds are, therefore, used for their glucogenic physiologic effect in cases where the... 

Steroid hormones are divided into six classes, based on physiological effects estrogens, androgens, progestins, glucocorticoids, mineralocorticoids and vitamin D 847... 

The primary glucocorticoid released in humans is cortisol (also known as hydrocortisone). Cortisol synthesis and secretion are under the control of specific hypothalamic and pituitary hormones.7,24 31 Corticotropinreleasing hormone (CRH) from the hypothalamus stimulates the release of adrenocorticotropic hormone (ACTH) from the anterior pituitary. ACTH travels in the systemic circulation to reach the adrenal cortex, where it stimulates cortisol synthesis. Cortisol then travels in the bloodstream to various target tissues to exert a number of physiologic effects (see Physiologic Effects of Glucocorticoids, later). 

Glucocorticoids exert a number of diverse physiologic effects, which are briefly discussed below. 

Monitor for adverse reactions from hydrocortisone administration. Glucocorticoid therapy at physiologic replacement doses should not lead to the development of Cushing s syndrome. However, careful monitoring should still be performed. Use the smallest effective dose. 

When given in larger than physiologic amounts, steroids such as cortisone and hydrocortisone, which have mineralocorticoid effects in addition to glucocorticoid effects, cause some sodium and fluid retention and loss of potassium. In patients with normal cardiovascular and renal function, this leads to a hypokalemic, hypochloremic alkalosis and eventually to a rise in blood pressure. In patients with hypoproteinemia, renal disease, or liver disease, edema may also occur. In patients with heart disease, even small degrees of sodium retention may lead to heart failure. These effects can be minimized by using synthetic non-salt-retaining steroids, sodium restriction, and judicious amounts of potassium supplements. 

Substitution therapy is used in cases of primary and secondary adrenocortical insufficiency the aim is to provide glucocorticoids and mineralocorticoids in physiological amounts, and the better the dosage regimen is adapted to the individual s needs, the less the chance of adverse effects (1). 

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