Corticosteroids Flashcards
prednisone
glucocorticoid
cortisol
glucocorticoid
aldosterone
mineralocorticoid
steroid hormones
lipophilic
-very hydrophobic
basal levels of glucocorticoids
diurnal
high in morning
cortisol feedback
negative on anterior pituitary and hypothalamus
also - inhibit immune system - lymphocytes, macros, monos, neutros
secondary adrenocortical insufficiency
iatrogenic
prolonged steroid therapy - HPA suppression
need gradual withdrawal**
cortisol effects
increase plasma glucose breakdown of lipid breakdown of protein increased vasoconstriction more RBCs, platelets, MPNs less eosinos, basos, monos, lymphos
inhibition of inflammatory mediators**
- prostaglandinds, leukotrienes, COX-2, mast cell
- decreased peripheral lymphos and macro activation
permissive effects
glucocorticoids induce proteins required for signal transduction by other hormones
establish endocrine set points or sensitivity for stimulation
mineralocorticoid specificity
MR - enzymatic protection so don’t respond to cortisol (which is always high)
11 beta hydroxysteroid dehydroxygenase
11 beta hydoxysteroid dehydroxygenase
converts cortisol to cortisone
in tissues that need aldosterone response to MR receptors and not high response to cortisol
glucocorticoids and inflammation
inhibit production and release of cytokines that normally stimulate proliferation and function of B and T cells
lipocortin mediated inhibition of PLA2
suppression/distribution of leukocytes
immune/CNS feedback
phospholipase A2
inhibited by corticosteroids
no arachidonic acid
-stops multiple downstream effects
inhibits multiple prostaglandin pathways
long acting steroids
betamethasone
dexamethasone
short acting steroids
cortisol
cortisone
mineralocorticoid steroids
corticosterone
fludrocortisone
intermediate acting steroids
more at glucocorticoid receptors
prednisone
prednisolone
methylprednisolone
triamcinolone
long acting very potent glucocorticoid
dexamethasone**
betamethasone
addisons disease
fludrocortisone**
corticosterone
triamcinolone
inhalation for asthma
dexamethasone
very potent
toxicity of corticosteroids
long term use - HPA axis suppression
corticosteroid
single dose or short course - no harmful effects
longer than 1 week - adverse weeks occur
alternate day therapy
minimize HPA suppression
pulse therapy
life-threatening conditions
initial dose large - if doesn’t work - us 2x or 3x dose
inhaled corticosteroids
low toxicity
