Corticosteroids Flashcards
Function of corticosteroids
Decrease inflammation and suppress immune system
Aldosterone action
Binds mineralocorticoid receptor to upregulate basolateral Na+/K+ ATPase gene expression in distal renal tubule
Effects of excess aldosterone
Hypernatremia, hypokalemia, metabolic alkalosis, edema
Function of cortisol
Increase glucose levels
Increase glycogen deposition
Increase fat deposition
Mineralocorticoid activity
Why does cortisol cause hypocalcemia
It breaks down proteins in lymphoid, muscles, skin, bone, connective tissues etc, resulting in negative nitrogen and calcium balance
Effects of steroids on inflammatory enzyme (COX-2, 5-LOX, PLA2) levels
Decrease
Effects of steroids on cytokines TNF-a, IL-1b, IL-6 levels
Decrease
Effects of steroids on b2-adrenoceptor level
Increase
Effects of steroids on IkB-a level
Increase
How does the body undergo feedback inhibition due to high cortisol levels in the body?
Decrease ACTH secretion to decrease endogenous cortisol production
What are the anti-inflammatory effects of steroids
- Decrease circulating WBCs via increased apoptosis, causing immunosuppresion
- Increase circulating neutrophils by increased production and decreased extravasation into inflamed tissue, causing them to remain in circulation
- Decrease size and lymphoid content of lymph nodes due to protein catabolic effect
- Effect on cellular immunity > humoral, slightly suppressed antibodies
- Increased macrophage efferocytosis and promotion of inflammation resolution
- Decreased type 4 delayed hypersensitivity
How is prednisolone superior to hydrocortisone?
Increased potency and duration of action than cortisol, less water retention than cortisol as well
How is triamcinolone different from prednisolone?
Addition of F
NO water retention, prevents increased aldosterone levels
How is dexamethasone different from triamcinolone?
Addition of methyl group increases potency drastically
Also no water retention
Standard steroid choice
Prednisolone
