Glucocorticoids & Sex Hormones 283absorption from intestine and enhance renal
excretion of Ca2+.
Antiinflammatory and immuno-
suppressive effects: Glucocorticoids suppress
all types of inflammation, hypersensitization
and allergic reactions. They suppress the edema,
capillary dilatation, migration of leukocytes,
capillary permeability in the inflamed area.
Glucocorticoids inhibit the functions of
leukocytes and tissues macrophages. They
also stabilize lysosomal membranes, thereby
reducing the concentration of proteolytic
enzymes at the site of inflammation.
Glucocorticoids also inhibit the
production of plasminogen activator by
neutrophils.
They also influence the inflammatory
response by reducing the prostaglandin and
leukotriene synthesis that results from
activation of enzyme phospholipase A 2.
Effect on CNS: Large doses of
glucocorticoids cause euphoria, mood
elevation, nervousness, restlessness, which
are reversible type of actions. They often
produce behavioural disturbances in human
being and also increase intracranial pressure.
Effect on CVS and blood: Glucocorticoids
inhibit capillary permeability and maintain
myocardial contractility and also the tone of
arterioles.
Glucocorticoids cause decrease in
number of circulating lymphocytes,
basophils and eosinophils in blood. They
increase the number of neutrophils, platelets
and erythrocytes.
Effect on GIT: Glucocorticoids stimulate
production of acid and pepsin in the
stomach and facilitate the development of
peptic ulcer.
Effect on kidney: In deficiency of
glucocorticoids, the glomerular filtration
rate is impaired.
Effect on endocrine system:
Glucocorticoids suppress the pituitary
release of ACTH and betalipotropin and
reduce secretion of FSH and TSH.Mechanism of Action
Most of the established pharmacological
effects of glucocorticoids are mediated by
cytoplasmic glucocorticoid receptors. After
binding to the receptor, the steroid-receptor
complex binds to chromatin and stimulate the
formation of mRNA. The mRNA stimulates
the synthesis of enzymes which produce
various pharmacological actions.Pharmacokinetics
They are given by oral, parenteral and
topical route. Oral bioavailability of synthetic
cortico-steroids is high. Hydrocortisone after
oral administration undergoes extensive first
pass metabolism in liver.
They are metabolised in liver and after
conjugation are excreted in urine. The
synthetic derivatives are metabolised slowly
and have longer duration of action.Adverse Reactions
GIT: Acute erosive gastritis and
haemorrhage. Peptic ulcer risk is increased.
Endocrine system: Cushing’s habitus,
hirsutism, retardation of growth, suppression
of hypothalamopituitary-adrenal axis.
Metabolic disorders: Hyperglycemia,
glycosuria and diabetes mellitus may be
precipitated, osteoporosis,
Eye: Glaucoma, cataract may develop.