Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Y2 - ENDO > Therapeutic uses of adrenal steroids > Flashcards

Therapeutic uses of adrenal steroids Flashcards

1
Q

List the 4 zones of the adrenal gland in order from outermost to innermost

A
  1. Zona Glomerulosa
  2. Zona Fasciculata
  3. Zona Reticularis
  4. Adrenal Medulla
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

In which zones of the adrenal gland are the following hormones produced?

1) Aldosterone
2) Cortisol
3) Sex steroids (androgens and oestrogen)

A

1) Zona Glomerulosa
2) Zona Fasciculata
3) Zona Reticularis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

In the steroid biosynthetic pathway, which hormones are under the control of ACTH secretion from the pituitary and which are not?

A
  • Cortisol (glucocorticoid) under control of ACTH
  • Sex steroids under control of ACTH
  • Aldosterone (mineralcorticoid) NOT under control of ACTH
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What controls the release of Aldosterone?

A
  • RAAS…
  • AT II stimulates the release of aldosterone from the zona glomerulosa
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Outline the RAAS system

A
  1. Angiotensinogen from liver
  2. Renin from kidneys released and converts angiotensinogen → ATI
  3. ACE from vascular endothelium in lungs converts ATI→ATII
  4. ATII stimulates aldosterone release from the zona glomerulosa
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the 4 triggers for aldosterone release?

A
  1. Hyperkalaemia
  2. Hyponatraemia
  3. Decreased renal blood flow - JGA detects this fall in renal blood flow and releases renin which stimulates aldosterone release via the RAAS system
  4. Beta-1 adrenoreceptor stimulation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Receptors for corticosteroids are members of the ….. and they include ….. receptors and ….. receptors

A

Receptors for corticosteroids are members of the nuclear receptor super-family and they include glucocorticoid receptors and mineralocorticoid receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Outline the properties of the glucocorticoid and mineralocorticoid receptors in terms of:

1) Distribution
2) Selectivity
3) Affinity for cortisol

A

1)

  • Glucocorticoid receptors have wide distribution
  • Mineralocorticoid receptors have discrete distribution

2)

  • Glucocorticoid receptors are selective for glucocorticoids
  • Mineralocorticoid receptors are unselective - can don’t distinguish between aldosterone and cortisol

3)

  • Glucocorticoids - Low affinity for cortisol
  • Mineralocorticoids - High affinity for cortisol
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What receptors can cortisol act on?

A
  • GR
  • MR
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How is cortisol prevented from acting on MR receptors, and in what situation is this overcome?

A
  • 11ß-HSD2 (dehydroxysteroid dehydrogenase) can act on cortisol to convert it into cortisone which is inactive
  • However XS cortisol will outcompete 11ß-HSD2 and act on the MR receptors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What will happen if XS cortisol acts on MR receptors?

A

It will have mineralocorticoid actions - causing hypokalaemia like in hyperaldosteronism or in Cushing’s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

List 4 adrenalcorticosteroid drugs, what they are analogues of, and their activity in relation to the mineralocorticoid/glucocorticoid activity

A
  1. Hydrocortisone - GLUCOCORTICOID with mineralocorticoid activity at high doses
  2. Prednisolone - GLUCOCORTICOID with weak mineralocorticoid activity
  3. Dexamethasone - GLUCOCORTICOID with NO mineralorcorticoid activity
  4. Fludracortisone - MINERALOCORTICOID which is an ALDOSTERONE ANALOGUE and NO glucocorticoid activity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Apart from as a glucocorticoid analogue, how else is Dexamethasone used clinically?

A
  • Used as an acute-anti oedema agent in brain metastases where there is often oedema with no mineralocorticoid effect
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

In terms of the pharmacokinetics of corticosteroids drugs…

1) What is the route of administration?
2) What is the distribution, and what is the one special case?
3) What is the duration of action (except for fludracortisone)?
4) What is the common route of excretion of these corticosteroid drugs?

A

1)

  • Oral administration - all of them
  • Parenteral (i.m or i.v) - hydrocortisone, dexamethasone

2)

  • Bind to plasma proteins (Cortisol Binding Globulin and Albumin) just like cortisol
  • Fludracortisone only binds albumin

3)

  • Dexamethasone - roughly 40 hours
  • Prednilosone - roughly 12 hours
  • Hydrocortisone - roughly 8 hours

4)

  • Hepatic breakdown and excretion via bile and urine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How to treat Addison’s disease (primary adrenocortical failure), and what is not that important to treat within it?

A
  • Fludracortisone to substitute for lack of aldosterone
  • Hydrocortisone to substitute for lack of cortisol
  • Don’t really need to treat for lack of adrenal androgens because the gonads also produce sex steroids
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

1) What is the pathophysiology of secondary adrenocortical failure and what does it cause?
2) So how do you treat?

A

1)

  • ACTH production failure
  • ACTH controls adrenal sex steroid and glucocorticoid release but NOT mineralocorticoid release
  • So patients lack cortisol and sex steroid but NOT aldosterone

2)

  • So treat with hydrocortisone
  • No need to treat for adrenal androgens becuase the gonads just produce these anyway
17
Q

How to treat Addisonian crisis - acute adrenocortical failure

A
  • Lack of cortisol and aldosterone in Addisonian crisis
  • Rehydration with Saline (0.9% sodium chloride)
  • 5% Glucose to treat hypoglycaemia
  • HIGH DOSE hydrocortisone to both have glucocorticoid effect and at high doses it overwhelms 11ß-HSD2 to have mineralocorticoid effect as well so you don’t need to give fludracortisone
18
Q

What are the symptoms of congenital adrenal hyperplasia?

A
  • DUE TO ACCUMULATION OF SEX STEROIDS…
  • In boys - precocious puberty
  • In girls - virilisation
  • In adult women - hirsutism / acne
  • HYPOALDOSTERONISM / LOW CORTISOL - BUT NO ADDISONIAN CRISIS (not that severe)
19
Q

How to treat congenital adrenal hyperplasia by 21-hydroxylase deficiency (complete or partial)?

A
  • Glucocorticoid substitute corticosteroids - dexamethasone and hydrocortisone - these also SUPPRESS ACTH BY NEGATIVE FEEDBACK INHIBITION so reduce adrenal androgen production
  • Mineralocorticoid substitute corticosteroid - fludracortisone
20
Q

How to monitor the therapeutic response to CAH therapy, in general and how to detect if dose is too low or too high?

A
  • Measure 17-hydroxyprogesterone levels
  • Cushingoid symptoms if dexamethasone / hydrocortisone dose is too HIGH
  • Hirsutism / acne if dexamethasone / hydrocortisone if dose is too LOW (because low negative feedback inhibition of ACTH so lots of adrenal androgen release)
21
Q

1) What is the normal level of cortisol production?
2) What is the level of cortisol production in stress?

A

1) 20 mg / day
2) 200-300 mg / day

22
Q

When should you adjust glucocorticoid dosage (excluding in terms of signs and symptoms recurrence) in the treatment of adrenocortical failure?

A
  • In times of stress, because there is usually physiological increase in cortisol production in response to stress
  • Minor illness - 2x dosage
  • Surgery
23
Q

What is the pathophysiology of iatrogenic adrenocortical failure?

A
  • Long-term, high dose corticosteroid therapy can foster dependence and decrease the body’s ability to produce cortisol by suppressing the HPA-axis

Y2 - ENDO (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions