corticosteroids 2 Flashcards
How do corticosteroids affect carbohydrate/protein metabolism?
- increase gluconeogenesis
- decrease peripheral utilisation of glucose
- increase glycogen deposition in the liver
How do corticosteroids affect lipid metabolism?
- cause redistribution of fat, Buffalo hump, moon face (Cushing’s effects)
- promote adipokinetic agents activity (glucagon, GH, AD, thyroxine)
How do corticosteroids affect electrolyte and water balance?
ALDOSTERONE
acts on distal convoluted tubule and collecting duct of the kidney
- increase Na reabsorption
- increase urinary excretion of K and H
electrolyte and water balance and corticosteroids and how it relates to Addison’s disease
Addison’s disease -> decreased aldosterone
- Na loss
- decreased K excretion (hyperkalaemia)
- decrease in ECF volume
How do corticosteroids affect the cardiovascular system?
restricted capillary permeability
maintain tone of arterioles
myocardial contractility
How do corticosteroids affect skeletal muscles?
needed for maintaining the normal function of skeletal muscles
What causes weakness and fatigue in Addison’s diaease?
inadequacy of the circulatory system
What can prolonged use of stroids lead to in relation to skeletal muscle?
skeletal muscle wasting
-> steroid myopathy
(weakness and fatigue)
How do corticosteroids affect the CNS directly?
mood
behaviour
brain excitability
How do corticosteroids affect CNS indirectly?
maintain glucose, circulation and electrolyte balance
What can increase in ICP lead to in relation to CNS?
pseudotumour cerebri
- intracranial hypertension
- headaches and vision problems
- rare
What increases the risk of pseudotumour cerebri?
glucocorticoids mineralocorticoids amiodarone vitamin A oral contraceptives tetracyclines
How do corticosteroids affect the stomach?
can cause peptic ulcers
- increased acid and pepsin secretion
- decreased immune response to H. Pylori
How do corticosteroids affect the blood (RBC)?
increase Hb and RBC content
How do corticosteroids affect the blood (WBC)?
decrease - lymphocytes, eosinophils, monocytes, basophils
increase - polymorphonucleocytes
Corticosteroids and anti-inflammatory and immunosuppressive effects
- they suppress of hypersensitivity and allergies
- high dose - interfere with steps of immunological response
- suppression of CMI (cell mediated immunity) in graft rejection
What do cortocosteroids suppress in anti-inflam/immunosuppression?
hypersensitivity and allergic reactions
How do corticosteroids help with transplant rejection?
decrease antigen expression from grafted tissue
delay revascularisation
decrease sensitisation of T lymphocyles
What effect do corticosteroids have on inflammatory cells?
- decrease neutrophil release
- decrease activation of neutrophils, macrophages, mast cells
- decrease activation of T-helper cells
- decrease switch from Th1 to Th2 immune response
corticosteroid effect on the infammatory mediators
- dec prostanoids
- reduced expression of COX2
- dec cytokines (IL2, IL-4, TNF alpha)
- dec nitric oxide synthase 2 (NOS2)
- dec complement
- dec histamine
- dec IgG production
- INCREASED synthesis of anti-inflamm mediators (IL-10, annexin-1)
summary of how steroids effect the immune system
block:
- T cell activation
- cytokine production
- mast cell release of histamine, PGs and leukotrienes
- eosinophils
What do steroids increase in their effect on the immune system?
increase anti-inflammatory factors
- IL-10
- IL-1
- annexin 1
How do corticosteroids work with calcium metabolism?
- decrease intestinal absorption
- increase renal excretion
- excessive loss of Ca from spongy bones (ribs, vertebrae)
- > osteoporosis
How do corticosteroids work on the respiratory system?
- effective anti-inflammatory
- effects not seen immediately (6hrs)
- inhaled used for long term use
