1 - SYSTEMIC CORTICOSTEROIDS Flashcards
The inactive form cortisone is converted to the active form cortisol (hydrocortisone) by 11 beta-hydroxysteroid dehydrogenase in the liver
True (both cortisone and cortisol/hydrocortisone are short acting corticosteroid)
The addition of a 1,2 double bond to cortisol (hydrocortisone) results in prednisone with increased glucocorticoid activity and decreased rate of metabolic degradation
True (prednisone is an intermediate acting corticosteroid)
Prednisolone is the active analog of prednisone (both intermediate acting corticosteroids)
True (prednisone is converted to prednisolone through 11-hydroxylation)
Prednisone is converted to its active analog prednisolone through 11-hydroxylation
True (both are intermediate acting corticosteroid)
Methylprednisolone is formed through the addition of a 6-methyl group to prednisolone (active analog of prednisone), which leads to slightly increased glucocorticoid activity
True (Methylprednisolone is an intermediate acting corticosteroid)
Cortisone and cortisol (hydrocortisone) are short acting corticosteroids
True
Prednisone, prednisolone (active analog of prednisone), Methylprednisolone and Triamcinolone are intermediate acting corticosteroids
True
Dexamethasone and betamethasone are long acting corticosteroids
True
The addition of fluorine to cortisol (hydrocortisone) leads to increased glucocorticoid but also significant mineralocorticoid activity and results in fludrocortisone
True
By modifying fludrocortisone (high glucocorticoid and mineralocorticoid activity), 3 compounds (Triamcinolone, dexamethasone and betamethasone) with high glucocorticoid and low mineralocorticoid effects are formed
True (all 3 compounds are biologically active due to the 11-hydroxyl group and do not require 11 beta-hydroxysteroid dehydrogenase for conversion to active form)
All corticosteroids have a hydroxyl group at the 17 position (17-hydroxycorticosteroids)
True
The long acting corticosteroids (dexamethasone and betamethasone) have higher glucocorticoid potency than the shorter acting corticosteroids (cortisone and cortisol/hydrocortisone)
True (prednisone, prednisolone, methylprednisolone and Triamcinolone are intermediate acting corticosteroids)
The shorter acting corticosteroids (cortisone and cortisol/hydrocortisone) have mineralocorticoid activity as compared to the longer acting corticosteroids (dexamethasone and betamethasone) which have little/no mineralocorticoid activity
True (there is an inverse correlation between the duration of action I.e. Potency and the relative mineralocorticoid effects)
Exogenous corticosteroid are absorbed in the upper jejunum
True
Food does not reduce the amount of prednisone absorbed
True (only delays absorption)
Food delays the absorption of prednisone
True (but does not reduce the amount absorbed)
80-90% of endogenous cortisol/hydrocortisone is bound to cortisol-binding globulin
True (the free fraction represents the active form)
The free fraction of cortisol is the active form
True
The primary endogenous carrier protein for cortisol is cortisol-binding globulin and it is a low capacity high affinity binding system
True (in contrast to albumin which is a high capacity but low affinity reserve)
The binding of synthetic exogenous corticosteroids to plasma proteins (cortisol-binding globulin or albumin) is less than the avidity with which endogenous cortisol is bound, hence a greater free fraction of exogenous corticosteroid is available
True
Prednisolone (active analog of prednisone) binds to plasma carrier proteins with greater affinity to other exogenous forms, with resultant potential for displacement of endogenous cortisol from the protein-binding sites
True
Cortisol-binding globulin is decreased in hypothyroidism which may result in increased amount of the endogenous and synthetic corticosteroid free fraction
True
Cortisol-binding globulin is decreased in liver disease which may result in increased amount of the endogenous and synthetic corticosteroid free fraction
True
Cortisol-binding globulin is decreased in renal disease which may result in increased amount of the endogenous and synthetic corticosteroid free fraction
True
Cortisol-binding globulin is decreased in obesity which may result in increased amount of the endogenous and synthetic corticosteroid free fraction
True
Cortisol-binding globulin is increased by estrogen therapy which may reduce the endogenous and synthetic corticosteroid free fraction
True
Cortisol-binding globulin is increased by pregnancy which may reduce the endogenous and synthetic corticosteroid free fraction
True
Cortisol-binding globulin is increased by hyperthyroidism which may reduce the endogenous and synthetic corticosteroid free fraction
True
High dose corticosteroid therapy results in greater proportion of corticosteroid free fraction
True
Prolonged corticosteroid treatment increase the corticosteroid free fraction
True
All endogenous and synthetic corticosteroid are well distributed into Fetal tissue except prednisone (inactive form)
True
Gluconeogenesis is a glucocorticoid effect that generates glucose at the expense of amino acids derived from endogenous proteins (glucose metabolism)
True
The glucocorticoid effect of Corticosteroids produce peripheral insulin resistance which impedes glucose absorption by various body tissues (glucose metabolism)
True
The glucocorticoid effect of corticosteroids is to enhance glycogen storage in the liver (glucose metabolism)
True
The glucocorticoid effect of corticosteroids is to stimulate lipid stores to undergo lipolysis, thus generating increased amounts of triglycerides for which to derive energy (lipid metabolism)
True
The net glucocorticoid effect of corticosteroids is a catabolic state that produces carbohydrates at the expense of protein and fat stores
True
The glucocorticoid effect of corticosteroids is to redistribute fat to central locations resulting in lipodystrophy that’s is characteristic for the body habitus in Cushing’s syndrome (lipid metabolism)
True
Corticosteroids are metabolised in the liver and extrahepatic sites to form relatively water soluble metabolites which are then excreted in the kidneys
True
11 beta-hydroxysteroid dehydrogenase in the liver is necessary to covert cortisone to cortisol (hydrocortisone), and to convert prednisone to prednisolone
True (therefore only cortisol and prednisolone are biologically active here)
Severe liver disease may impair the conversion of cortisone to cortisol (hydrocortisone) and prednisone to prednisolone by 11 beta-hydroxysteroid dehydrogenase
True (therefore prednisolone is more appropriate in patients with liver disease than prednisone)
The administration of prednisolone rather than prednisone to patients with advanced liver disease is appropriate
True (as conversion of prednisone to prednisolone is mediated by 11 beta-hydroxysteroid dehydrogenase in the liver)
The plasma half lives of the various exogenous synthetic corticosteroids do not correlate well with the duration of biological activity I.e. Short, intermediate, long acting (potency)
True (a much more important measure of duration of activity is the duration of ACTH suppression after the administration of a single dose of corticosteroid)
The duration of activity of corticosteroids correlate well with glucocorticoid and anti-inflammatory effects (potency)
True
There is an inverse correlation between the duration of action and the relative mineralocorticoid effects of corticosteroids
True (long acting dexamethasone and betamethasone don’t have mineralocorticoid activity, in contrast to short acting cortisone and cortisol/hydrocortisone)
Prednisone and prednisolone (intermediate acting corticosteroid) have mild mineralocorticoid activity
True (in contrast to the other intermediate acting corticosteroid methylprednisolone and Triamcinolone which do not exhibit mineralocorticoid activity)
The hypothalamus secretes CRF (corticotropin-releasing factor) which stimulates the anterior pituitary gland to produce ACTH
True
The anterior pituitary gland secretes ACTH (adrenocorticotrophic hormone) which stimulates the zona fasciculata of the adrenal cortex to produce and release cortisol
True
ACTH from the anterior pituitary gland also stimulates adrenal androgen synthesis
True
ACTH from the anterior pituitary gland is not involved in stimulating the release of the mineralocorticoid aldosterone from the adrenal glands
True
The basal production of cortisol of 20-30mg daily is equivalent to 5-7.5mg of prednisone daily
True
The maximal stress production of cortisol of 300mg daily is equivalent to 75mg daily of prednisone
True
The minor stress production of cortisol is about 2-3 times the basal production of 20-30mg daily
True
The hypothalamus is the first to be suppressed and the first to recover full function in response to exogenous corticosteroids and stress
True (therefore the hypothalamus is the most important part of the HPA-axis in terms of stress responsiveness)
The adrenal gland is the slower to be suppressed and much slower to recover full function in response to exogenous corticosteroids and stress
True
CRF from the hypothalamus (and hence ACTH from the anterior pituitary gland) have innate diurnal variations tied to sleep cycle with the highest production in mid-sleep and the lowest production in late afternoon
True
Increased cortisol levels reduce CRF and ACTH production
True
In response to stress, there is increased CRF release from the hypothalamus and subsequently increased ACTH release from the anterior pituitary
True
The hypothalamo-pituitary-adrenal axis serves to maintain glucose homeostasis
True
Corticosteroids play a role in maintaining adequate glucose levels for brain function
True
ACTH has no role in endogenous mineralocorticoid (aldosterone) production
True (the control is through the renin-angiotensin system and and serum potassium levels)
Aldosterone is the primary endogenous mineralocorticoid hormone
True
The primary effect of aldosterone is sodium reabsorption resulting in water reabsorption at the proximal tubule in the kidneys
True (as sodium is exchanged for potassium, an excessive mineralocorticoid effect leads to hypokalaemia)
Corticosteroid with significant mineralocorticoid effects I.e. Hydrocortisone have a similar effect on sodium, potassium, and fluid balance as aldosterone
True
Potassium is exchanged for sodium at the proximal tubules of the kidneys as a result of mineralocorticoid effects of aldosterone, and excessive mineralocorticoid effect may lead to hypokalaemia
True
Aldosterone production and regulation is via the renin-angiotensin system
True
The major priority for mineralocorticoids is to maintain sodium and fluid homeostasis, including normal blood pressure
True
There is only 1 glucocorticoid receptor (located in the cytoplasm) which accounts for the endogenous glucocorticoid effects as well as the pharmacological effects of synthetic corticosteroids
True
There are rare cases of hereditary glucocorticoid resistance, in which there are mutations in the glucocorticoid receptor (GCR) gene
True (although there are also cases of relative resistance which lack mutations or polymorphisms in the GCR gene)
Relative resistance to corticosteroids is due to altered corticosteroid bioavailability, altered ligand binding to the cytosolic glucocorticoid receptor (GCR), or altered translocation of the activated GCR complex to the nucleus and could represent a negative feedback system, with downregulation of the GCR after prolonged or high dose corticosteroid therapy
True
The 2 well described transcription factors with a central role in the amplification on the inflammatory response as a result of corticosteroids are nuclear factor kappa B (NFkB) and Activating Protein-1 (AP-1)
True (there is tremendous overlap with the inflammatory response genes induced by NFkB and AP-1)
Nuclear factor kappa B (NFkB) is biologically inactive as long as it is bound to inhibitor kappa B (IkB), and NFkB is activated when any biological stimuli degrades IkB, thus freeing NFkB to be a biologically active transcription factor
True (coricosteroids increase production of IkB, therefore resulting in reduced free NFkB)
Corticosteroids reduces the effects of Nuclear factor kappa B (NFkB) in 2 ways - (1) increase the production of Inhibitor kappa B (IkB), resulting in more NFkB being bound to IkB leading to decreased free NFkB
(2) directly bind to free NFkB and thereby inhibiting the transcription factor
True
Corticosteroids can directly induce apoptosis in lymphocytes and eosinophils
True (this could explain the effect of corticosteroid in autoimmune disorders, allergic disorders, and neoplastic disorders)
The effect of corticosteroids in inducing apoptosis in lymphocytes and eosinophils may be an a underlying explanation for corticosteroid effects in autoimmune disorders (apoptosis of auto-reactive T cells), allergic disorders (apoptosis of eosinophils), and certain neoplastic disorders (apoptosis of malignancy T cells)
True
Systemic fungal infections is an absolute contraindication for systemic corticosteroid therapy
True
Herpes simplex keratitis is an absolute contraindication for systemic corticosteroid therapy
True
Hypertension is a relative contraindication for systemic corticosteroid therapy
True (mineralocorticoid effect of sodium retention and glucocorticoid induced vasoconstriction worsens hypertension)
Congestive cardiac failure is a relative contraindication for systemic corticosteroid therapy
True (mineralocorticoid effect of sodium reabsorption and water reabsorption causing fluid overload)
Prior psychosis is a relative contraindication for systemic corticosteroid therapy
True (corticosteroids possibly precipitate this due to electrolyte shifts, altered nerve excitability, mild cerebral oedema from sodium and water retention)
Severe depression is a relative contraindication for systemic corticosteroid therapy
True
Active peptic ulcer disease is a relative contraindication for systemic corticosteroid therapy
True (corticosteroid may cause reduced mucus production and increased acid secretion)
Recent bowel anastomosis is a relative contraindication for systemic corticosteroid therapy
True (glucocorticoid catabolic effects producing decreased wound healing)
Active TB is a relative contraindication for systemic corticosteroid therapy
True (immunosuppressive effect of corticosteroids)
A positive tuberculin skin test is a relative contraindication for systemic corticosteroid therapy
True (immunosuppressive effect of corticosteroid and TB reactivation)
Diabetes is a relative contraindication for systemic corticosteroid therapy
True (corticosteroid effect on glucose metabolism resulting in hyperglycaemia)
Osteoporosis is a relative contraindication for systemic corticosteroid therapy
True (corticosteroid effect on bone metabolism resulting in increased osteoclasts activity, decreased osteoblast activity, decreased GI absorption of calcium, increased renal excretion of calcium - secondary hyperparathyroidism and bone resorption)
Cataracts is a relative contraindication for systemic corticosteroid therapy
True (corticosteroids cause altered lens proteins)
Glaucoma is a relative contraindication for systemic corticosteroid therapy
True
Pregnancy is a relative contraindication for systemic corticosteroid therapy
True
Systemic Corticosteroids can cause hyperlipidaemia due to lipolysis and fat redistribution
True
Systemic corticosteroids cause Cushingoid changes due to altered fat distribution from overall fat catabolism
True
Systemic corticosteroids may case growth impairment due to reduced growth hormone production resulting in delays skeletal maturation
True
Systemic corticosteroids may cause myopathy due to reduced glucose and amino acid uptake by muscle cells, leading to muscle atrophy and wasting
True
Systemic corticosteroids have a greater effect on T cells than B cells
True (B cell effects are more evident with higher doses of corticosteroids)
Systemic corticosteroids inhibit granulation of mast cells, resulting in decreased histamine release
True
Systemic corticosteroids reduce angiogenesis in wound healing and in proliferative lesions I.e. Haemangiomas
True
Systemic corticosteroids causes vasoconstriction
True
Brief bursts of systemic corticosteroids for 2-3 weeks is surprisingly safe and useful in self-limiting dermatoses
True