Pharmacology for Anaesthesia and Intensive Care

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Corticosteroids and other

hormone preparations

Glucocorticoids


Drugs used in thyroid disease


Oral contraceptives


Hormone replacement therapy

Glucocorticoids

The adrenal cortex releases two classes of steroidal hormones into the circulation:


Glucocorticoids (from the zona fasciculata and zona reticularis)


Mineralocorticoids (from the zona glomerulosa)

The main endogenous glucocorticoid in humans is hydrocortisone. Synthetic gluco-

corticoids include prednisolone, methylprednisolone, betamethasone, dexametha-

sone and triamcinolone. They havemetabolic, anti-inflammatoryandimmuno-

suppressiveeffects.

Metabolic effects

Glucocorticoids facilitate gluconeogenesis (i.e. synthesis of glucose from a non-

carbohydrate source, e.g. protein). Glycogen deposition and glucose release from

the liver are stimulated but the peripheral uptake of glucose is inhibited. Protein

catabolism is stimulated and synthesis inhibited.

When exogenous glucocorticoid is given in high doses or for prolonged periods, the

altered metabolism causes unwanted effects. Increased protein catabolism leads to

muscle weakness and wasting. The skin becomes thin leading to striae, and gastric

mucosa becomes susceptible to ulceration. Dietary protein will not reverse these

changes. Altered carbohydrate metabolism leads to hyperglycaemia and glycosuria.

Diabetes may be provoked. Fat is redistributed from the extremities to the trunk,

neck and face. Bone catabolism leads to osteoporosis.

Anti-inflammatory effects

Glucocorticoids reduce the production of tissue transudate and cell oedema in acute

inflammation. Circulating polymorphs and macrophages are prevented from reach-

ing inflamed tissue. The production of inflammatory mediators (prostaglandins,

leukotrienes and platelet-activating factor) is suppressed by the stimulation of

lipocortin, which inhibits phospholipase A 2 .Normally phospholipase A 2 would