-
adrenocorticosteroids
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glucocorticoids
- intermediate metab & immune func
-
naturally occuring
-
major : cortisol (hydrocortisone)
- synthesized from cholesterol
- synthesis/ secretion regulated by CNS
- metab by liver
-
pharmacokinetics
- secretion governed by corticotropin (ACTH)
- corticosteroid- binding globulin (CBG)- alpha2 globulin made by liver- binds 90%
- remainder is free or loosly bound to albumin & avail to act...consider free
- CBC inc in prego, estrogen stim, hyperthyroidism
- CBC dec in hypothyroidism, genetic defects in synthesis, protein deficiency states
-
MOA
- physiologic
- vascular/ bronchial sm myo response to catecholamines is diminished if cortisol missing & restored by glucocorticoid
- lipolytic response to fat cells to catecholamines, ACTH, GH are dec if glucocorticoids absent
- metabolic
- stimulate/ req'd for gluconeogenesis & glycogen synthesis in fasting state
- inc glucose levels therefore stim insulin release & inhib lipolysis (inc fat)
- catabolic/antianabolic
- supra levels lead to dec myo mass, weakness, & thinning of the skin
- osteoporosis in Cushings syn...avoid long term use
- in children- reduce growth
- can be prevented by admin GH in high doses
- antiinflamm/ immunosupp
- due to effects on conc, distrib, and funct of peripheral leukocytes & suppressive effects on inflam cytokines and chemokines
- after dose of SA glucocorticosteroid, conc of neutophils inc, while lymphocytes, monocytes, eosinophils, basophils dec
- inhib funct of tissue macrophages and other antigen-presenting cells
- influence inflamm response by reducing the prostaglandin, leukotriene, and platelet-activating factor synthesis resulting from activ phospholipase A2
- reduce expression of cyclooxygenase-2, reducing prostaglandins
- cause vasoconstriction, & dec capillary permeability by reducing the amt of histamine prod
-
SE
- insomnia, euphoria, depression
- inc intracranial pressure
- supress the pituitary release of ACTH, GH, thyroid stim hormone, LH if given chronically
- peptic ulcer, fat redistribution, dec calcium absorption
- inc # of platelets and RBC
-
deficiency
- impaired renal func, augmented vasopression secretion, & diminished ability to excrete a water load
-
synthetic
-
Short/ medium acting
- hydrocortisone
- tx: chronic Addisons disease (chronic adrenocortical insuff) w/ fludorcortisone
- tx: acute Addison's disease (parenteral) + fluids/electolytes
- tx: congenital adrenal hyperplasia + prednisone + fludrocortisone + salt
- tx: Cushing's syndrome
- cortisone
- prednisone
- prodrug
- prednisolone
- methylprednisone
-
intermed acting
- triamcinolone
-
long acting
- betamethasone
- used to stim fetal lung maturation
- inc transfer across placenta than others
- dexamethasone
- tx to prevent congenital adrenal hyperplasia (given to mother)
- used for diagnostic purposes : Cushings syn, depressive psych states (pseudo-cushings syn)
- used for tx of transplant rejection
- dose must be tapered down
- prolonged therapy: perform x-ray & TB test
-
contraindicated
- peptic ulcer, heart disease, HTN w/ heart failure, varicella, TB, phycoses, diabetes, osteoporosis, glaucoma
-
mineralcorticoids
- salt-retaining activity
- major: aldosterone
-
fludrocortisone
- tx: Addison's disease w/ hydrocortisone
- tx: aldosteronism
-
androgenic
- major: dehydoepiandrosterone (DHEA)
- estrogenic
-
adrenocortical antagonists
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aminoglutethimide
- blocks conversion of cholesterol to prenenolone and causes reduction of all hormonally active steroids
- used w/ hydrocortisone or dexamethasone to reduce/eliminate estrogen production in breast cancer
- tx cushings syn
-
ketoconazole
- antifungual imadazole deriv
- potent/ non-selective inhib of adrenal & gonadal steroid synthesis
- tx cushings syn
-
metyrapone
- selective inhib of steroid 11-hydroxylation (interfere w/ cortisol & corticosterone synthesis)
- tx: Cushings syn
- can be admin to prego wm
-
abiraterone
- blocks 17a-hydroxylase and 17,20 lyase & reduces synthesis of cortisol and gonadal steroids
- tx: refractive prostate cancer
-
mifeprostone (ru-48)
- antagonist at the steroid receptor
- strong anti-progestin activ
- tx: inoperable pts w/ ectopic ACTH secretion or adrenal carcinoma
-
mineralcorticoid antagonists
- spirinolactone
-
eplerenone
- has no effect on androgen receptors
-
drospirenone
- progestin on oral contraceptives