Adrenocorticosteroids Flashcards
(44 cards)
Hormonal Steroids Overview?
• Glucocorticoids
Effects on intermediary metabolism and immune function
• Mineralocorticoids
Principally salt-retaining activity
• Steroids with androgenic and estrogenic activity
Naturally occurring glucocorticoids? MOA?
• Cortisol (Hydrocortisone)
Synthesis & secretion tightly regulated by CNS
Mechanism of Action
• Effects mediated by widely distributed glucocorticoid
receptors
• Steroid-receptor complex enters the nucleus and interacts
with promoters of (and regulates the transcription of) target genes
• Produce tissue-specific responses
Metabolic Effects of Cortisol?
• 95% of hormonal activity is due to cortisol
Metabolic Effects
• Stimulates and is required for gluconeogenesis &
glycogen synthesis (which maintains hepatic glycogen
availability) in fasting state
→ increase serum glucose levels (thus leading to stimulation of insulin release) & inhibiting uptake by muscle cells
• Stimulates lipolysis (leading to fat deposition and
redistribution & increased release of fatty acids & glycerol)
• Stimulates protein catabolism & release of amino acids
Net Result: Maintenance of an adequate glucose
supply to brain (most apparent in fasting state)
Catabolic Effects of Hydrocortisone?
Catabolic Effects
• In addition to protein catabolism, cortisol also has effects in lymphoid and connective tissue, muscle, peripheral fat and skin (wasting occurs at high concentrations)
• Catabolic effects on bone = osteoporosis
• In children = growth retardation
Both are major limitations in long-term treatment with
glucocorticoids.
Immunosuppressive Effects of Cortisol(Hydrocortisone)?
• Effects on leukocytes
• Increased neutrophils (increased influx into blood & decreased migration from blood vessels)
• Decreased lymphocytes (T and B cells),
monocytes, eosinophils and basophils (movement
from vascular bed to lymphoid tissue)
• Vasoconstriction due possibly to suppression of mast cell degranulation
• Decreased histamine release and capillary
permeability
Anti inflammatory effects of Cortisol(hydrocortisone)?
• Inhibition of phospholipase A2
(through induction &
activation of annexin I) which blocks arachidonic acid release (major precursor of prostaglandins).
• Cyclooxygenase-2 synthesis is reduced (through inhibition of NF-kB).
• Induction of MAPK phosphatase I (inhibits MAPK activated proinflammatory signaling pathways).
Other effects of Cortisol (Hydrocortisone)?
• CNS: behavioral changes (insomnia, euphoria leading to depression)
• Increased intracranial pressure: large doses
• Suppression of release of ACTH, growth hormone,
thyroid-stimulating hormone & luteinizing hormone: chronic use
• Peptic Ulcers: Stimulation of gastric acid. Suppression of immune response to H.pylori?
• Increase platelets & RBCs
• Renal function: is impaired with cortisol deficiency
• Development of fetal lungs
Cortisol PK?
- Relatively short duration of action
- Diffuses poorly across skin (unless inflamed)
- Diffuses well across mucous membranes
- Some salt-retaining effects
Name 2 mineralocorticoids? Describe each
Aldosterone
Fludrocortisone
• Aldosterone
Most important mineralocorticoid in humans
• Fludrocortisone
Synthetic corticosteroid. Most commonly prescribed salt retaining
hormone
Name 6 glucocorticoids?
Prednisone Hydrocortisone Dexamethasone Beclomethasone Triamcinolone Methylprednisolone
Name 5 synthetic glucocorticoids?
- Prednisone
- Methylprednisolone
- Dexamethasone
- Beclomethasone
- Triamcinolone
PK of synthetic glucocorticoids?
- Rapidly and completely absorbed orally
- Selected compounds can also be given IV, IM, topically, intra-articularly & by aerosol
- Long t1/2’s
- Reduced salt-retaining effects
Route of administration for glucocorticoids?
Oral?
IM?
Aerosol?
Oral: All can be given orally
IM: Triamcinolone
Aerosol: Beclomethasone
Triamcinolone
ROA glucocorticoids?
IV, IM?
IV,IM: Dexamethasone Hydrocortisone Methylprednisolone Prednisolone
ROA glucocorticoids?
Topical: Beclomethasone Dexamethasone Hydrocortisone Triamcinolone
MOA of Mineralocorticoids?
Mechanism of Action
• Bind to mineralocorticoid receptor
• Drug-receptor complex acts in similar fashion to
glucocorticoid drug-receptor complex
• Major effect of activation of the aldosterone receptor:
• increased expression of Na+ /K+ ATPase
• increased expression of ENaC
Major effects of Mineralocorticoids?
• Natural mineralocorticoid = Aldosterone
• Major role are as salt-retaining hormones
• Under control and regulation of CRH, ACTH and renin angiotensin
system
• Help to control body’s water volume & electrolyte
concentrations (Na+ & K+)
• promote Na+
reabsorption from renal tubule
• promote K+ and H+ excretion
AE of Mineralocorticoids?
- Hypokalemia
- Metabolic alkalosis
- Increased plasma volume
- Hypertension
Short- to medium acting
glucocorticoids anti-inflammatory to salt retaining ratio?
Hydrocortisone
Prednisone
Methylprednisolone
anti-inflammatory to salt retaining ratio
Hydrocortisone 1:1
Prednisone 4:0.3
Methylprednisolone 5:0.25
Intermediate acting
glucocorticoids and Long-acting glucocorticoids anti-inflammatory to salt retaining ratio?
(intermediate)Triamcinolone
(long acting)Dexamethasone
anti-inflammatory to salt retaining ratio
Triamcinolone 5:0
Dexamethasone 30:0
Mineralocorticoids anti-inflammatory to salt retaining ratio?
Fludrocortisone
Aldosterone
anti-inflammatory to salt retaining ratio?
Fludrocortisone 10:250
Aldosterone 0.3:3000
Undiagnosed acute adrenocortical insufficiency attack treatment?
Undiagnosed Acute attack
Treat with dexamethasone to avoid interference with
testing of cortisol levels.
Fluid and electrolyte replacement are essential
acute adrenocortical insufficiency causes and treatment?
Associated with life-threatening shock, infection or trauma
Treatment should be started immediately
For patients with previous diagnosis:
Large amounts of parenteral corticosteroids +
correction of fluid & electrolyte abnormalities
Can administer salt-retaining hormone once hydrocortisone levels are reduced (~ 5 days)
Chronic adrenocortical insufficiency (addison’s disease) characterization and treatment?
Characterized by weakness, fatigue, weight loss, hypotension, hyperpigmentation, inability to maintain blood glucose levels during fasting
Treatment
Daily oral hydrocortisone (increase dose during stress)
+ mineralocorticoid (fludrocortisone)
DO NOT administer glucocorticoids lacking salt retaining effects