11 - Glucocorticoids Flashcards

1
Q

Are adrenocorticoids the same as androgens?

A

NO

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

What causes the body to induce production of adrenocorticoids?

A
  • Stress
  • Stress causes release of corticotropin releasing hormone (CRH) from hypothalamus, stimulating release of adrenocorticotropic hormone (ACTH) from pituitary gland, which stimulates uptake of LDL into adrenal cortical cells to produce adrenocorticoids
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the most important adrenocorticoids?

A

Cortisol (hydrocortisone) and aldosterone

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

What are the functions of glucocorticoids?

A
  • Stimulate gluconeogenesis (liver)
  • Stimulate bone loss
  • Suppress production of inflammatory mediators, “turning down” immune activity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the main mechanism of action for anti-inflammatory effects of glucocorticoids?

A
  • GCs stimulate production of lipocortin (cytosolic protein) that is believed to bind to membrane phospholipids, preventing phospholipase A2 (PLA2) from hydrolyzing ester linkage btwn phospholipid and arachidonic
  • Arachidonic acid can’t be released => less production of prostaglandins, leukotrienes, and platelet activating factor inflammatory mediators
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the outcome of glucocorticoids anti-inflammatory effects?

A

Inhibition of macrophages in tissues, neutrophils in or near blood, and eosinophils in bronchi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

___ is responsible for the majority of glucocorticoid effects

A

Hydrocortisone

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

What is the difference btwn hydrocortisone and cortisone? How are they interconverted?

A
  • Hydrocortisone has OH at C-11; cortisone has =O

- Dehydrogenase converts hydrocortisone to cortisone; reductase converts cortisone to hydrocortisone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Why is hydrocortisone not stored in LDL and HDL particles?

A

B/c it is a stress hormone, so we only want it around when it is immediately needed

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

What are some adverse effects of glucocorticoids?

A
  • Infections
  • Osteoporosis
  • Increased CV risk
  • Myopathy
  • Weight gain/obesity
  • Gastric ulcer
  • Skin thinning
  • Glaucoma, cataract
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the primary use of glucocorticoids as drugs?

A

Suppression of inflammation

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

What are the routes of administration for glucocorticoids as drugs? What is most common?

A

Oral, IV, IM, inhaled, and topical (most common is topical)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What preparations is hydrocortisone used in?

A

Ointments and creams (but not o/w lotions) to enhance dermal uptake

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Are synthetic glucocorticoids more or less potent than natural glucocorticoids?

A

More potent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Does hydrocortisone produce any active metabolites?

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Does prednisolone produce any active metabolites?

A

Yes

17
Q

What is the difference btwn prednisone and prednisolone?

A

Prednisone is the prodrug form of prednisolone

18
Q

When is prednisolone used instead of prednisone?

A

In px w/ hepatic failure, b/c they won’t be able to convert the prodrug to the active form

19
Q

Is hydrocortisone more active than betamethasone?

A

No, betamethasone is 30X more active

20
Q

Rank from most active to least active – hydrocortisone, betamethasone, dexamethasone

A

Betamethasone > dexamethasone > hydrocortisone

21
Q

How are glucocorticoids metabolized?

A
  • Reduction of double bond at C-4 and C-5

- Reduction of ketone in C-3 to hydroxyl group

22
Q

What happens to the inactive metabolites of glucocorticoids?

A

Enzymatically coupled through C-3 hydroxyl w/ sulfate or glucuronic acid to yield more water soluble compounds, which are excreted via kidneys

23
Q

What does the presence of a double bond at C1 and C2 and a fluorine at C6 or C9 of a glucocorticoid cause?

A
  • Increased resistance to degradation
  • Reduced clearance
  • Prolonged effects
24
Q

What is involved in the secondary deactivation pathway for glucocorticoids?

A

Oxidation at positions C-21 and C-6

25
Q

What effect does fluorination at C-6 or C-9 have on hydroxylation?

A

Slows hydroxylation at C-6

26
Q

Do glucocorticoids have high or low plasma protein binding?

A

Very high, over 90%

27
Q

What can long-term administration of glucocorticoids cause?

A
  • Adrenal suppression
  • High BP
  • Hyperglycemia
  • Glaucoma
  • Osteoporosis
  • Reduced immune system function
28
Q

What can abruptly ceasing glucocorticoid use cause?

A

Hypocortisolism; hyperpigmentation of skin

29
Q

What is done to synthetic glucocorticoids to prevent systemic uptake from lungs or GI tract?

A

Designed to be highly lipophilic

30
Q

What is the effect of steroid hormones on salt and water balance?

A
  • Increase production of Na+/K+ transporter protein
  • Increase production of Na+/H2O reabsorption
  • Increase K+ excretion
31
Q

How are the effects of mineralocorticoid mediated?

A
  • Slow genomic mechanisms through nuclear receptors

- Fast non-genomic mechanisms through membrane-associated receptors or signalling cascades

32
Q

What are some characteristics of aldosterone?

A
  • Agonist
  • Highly potent
  • Never used as a drug b/c too potent, so would cause too many SE
33
Q

What is used for aldosterone replacement therapy for aldosterone insufficiency?

A

Fludrocortisone

34
Q

What are some characteristics of spironolactone?

A
  • Antagonist of aldosterone receptors
  • Orally bioavailable
  • Major metabolite is very active
  • K-sparing diuretic
35
Q

Glucocorticoids w/ a ___ are generally used for injectables

A

Salt

36
Q

What is the difference between dexamethasone, betamethasone, and paramethasone?

A
  • Dexamethasone has fluorine at C-9 and conformation at C-16 is alpha
  • Betamethasone has fluorine at C-9 and conformation at C-16 is beta
  • Paramethasone has fluorine at C-6 and conformation at C-16 is alpha