Endocrine Pharmacology Flashcards

1
Q

Adrenal steroids are manufactured by enzymes located in the:

A

Mitochondria and SER

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

Three primary pathways (adrenal cortex)

MGA

A
  1. Mineralocorticoid
  2. Glucocorticoid
  3. Androgen/estrogen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Precursor for steroid biosynthesis

A

Cholesterol

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

Synthesis and secretion is controlled by CRH from the hypothalamus and ACTH from the pituitary

A

Cortisol / hydrocortisone

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

Steroid binding proteins

A
  • Corticotropin binding globulin (CBG) aka transcortin
  • Albumin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

MOA: Glucocorticoids

A

● Steroids exert their effects by altering protein synthesis through a direct effect
on the cell’s nucleus
● glucocorticoids first enter the cell and bind to a receptor in the cytosol
● ”hormone-receptor“ complex (transcription factor)
● this complex travels (translocates) to the nucleus
● binds to specific DNA gene segments that control inflammation and other
processes
● transcription factor:
○ modulates the transcription of DNA mRNA units
○ inhibits other transcirption factors (nuclear factor-kappa B, activator
protei-1) that normally activate inflammatory genes
■ thus, turning off proinflammatory genes and suppressing the
production of inflammatory products
● Changes in mRNA transcription ultimately lead to a change of protein
synthesis in the cell

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

MOA: Glucocorticoids

Rapid effect mediated by

A

Surface receptors

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

MOA: Glucocorticoids

Delayed effect

A

more prolonged; mediated by intracellular receptor; affects
transcription at the genomic level

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

MOA: Glucocorticoids

Genomic effects

A

takes SEVERAL HOURS OR DAYS TO OCCUR because of the time required to alter protein synthesis and create new proteins that reach meaningful concentrations in the cell

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

Physiological Effects: Glucocorticoids

AEI

A

● Anti-inflammatory
● immunosuppresion
● Effects on Glucose, Protein, and Lipid Metabolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Glucocorticoid Effect on Glucose, Protein, and Lipid Metabolism

A

● increase blood glucose
● increase liver glycogen
● inhibits the uptake of glucose into muscle and fat
● muscle breakdown to amino acids
● lipid breakdown to free fatty acids

Effects:
● maintain blood glucose levels and liver glycogen
levels
● enables a supply of energy substrate readily
available for increased activity

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

Anti-inflammatory Effects: Glucocorticoids

A

Attenuate the heat, swelling, and tenderness regardless of the cause

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

glucocorticoids act on macrophages, lymphocytes, and endothelial cells to
inhibit inflammatory proteins (cytokines):

A

○ IL-1, IL-6, TNF alpha, IFN gamma,
■ Primary chemical signal for activating other inflammatory cells (T lymphocytes, fibroblasts, NK cells)

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

Anti-inflammatory effects: Glucocorticoids

A

reduce the number of circulating lymphocytes, eosinophils, and other cells

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

Anti-inflammatory effects: Glucocorticoids

inhibit the transcription and expression of adhesion molecules:

A

endothelial leukocyte adhesion molecule 1, intracellular adhesion
molecule 1

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

responsible for attracting leukocytes in the bloodstream to
endothelial cells at the site of inflammation

A

endothelial leukocyte adhesion molecule 1, intracellular adhesion
molecule 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Anti-inflammatory Effects: Glucocorticoids

Inhibit the production of proinflammatory substances:

A

prostaglandins and
leukotrienes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Anti-inflammatory Effects: Glucocorticoids

activate genes to synthesize annexins / lipocortins

A

inhibits phospholipase A2 enzyme

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

● inhibit hypersensitivity reactions, especially delayed or cell-mediated allergic
reactions
● suppress the ability of immune cells to synthesize or respond to chemical
mediators such as cytokines that promote autoimmune responses

A

Immunosupression

20
Q

Other effects of Glucocorticoids

A

● Enhances sodium and water reabsorption by impairing the ability of the
kidneys to excrete water
● Alter CNS function: changes in behavior and mood
● decreased vascular permeability

21
Q

○ destruction of adrenal cortex
○ autoimmune
○ nonspecific symptoms
○ acute adrenal crisis: hypotension, hyponatremia,
hyperkalemia, hypoglycemia
○ low cortisol and aldosterone levels
○ high renin levels
○ blunt cortisol reponse with ACTH stimulation
○ life threatening; severe endocrine emergency
○ life-long treatment with hormonal replacement is needed
○ Hydrocortisone, identical to cortisol, is given to correct the
deficiency
○ Fludrocortisone, a potent synthetic mineralocorticoid may
also be necessary

A

Primary adrenal insufficiency / Addison
disease / autoimmune adrenalitis

22
Q

Glucocorticoid use in Nonendocrine
Conditions

A

● Collagen diseases
● Autoimmune disorders
○ Rheumatic disorders (Rheumatic arthritis)
● musculoskeletal injuries
● tenosynovitis
● myositis
● back and neck pain
● Carpal Tunnel Syndrome
● Joint inflammation
○ rule of thumb: limit glucocorticoid injection to a specific joint to 4 or < per year
● Allergies, allergic rhinitis, asthma (fluticasone)
● Acceleration of lung maturation in preterm newborn (dexamethasone, betamethasone)
● Cerebral edema (dexamethasone) to suppress inflammation and angiogenesis

23
Q

Adverse effects: Glucocorticoids

A
  • Adrenocortical suppression
  • Drug-induced Cushing Syndrome
  • Breakdown of supporting tissues
  • Osteoporosis
24
Q

Adrenocortical suppression

A

○ Negative feedback to the hypothalamic-anterior pituitary (HPA) axis is
caused by the administration of exogenous hormones
■ to prevent this, alternate-day administration, to allow the HPA axis
to recover/function
○ abrupt withdrawal of therapy can also be life-threatening, it must be
withdrawn slowly by tapering the dose

25
Q

Breakdown of Supporting Tissues

A

○ Involves muscle, bone, ligaments, tendons
○ The magnitude of wasting depends on the duration and dosage of drug
therapy including the patient’s overall health
○ PTs must be careful to avoid overstressing weakened tissues

26
Q

Osteoporosis

A

○ glucocorticoids suppress Calcium absorption in the intestines, inhibit
bone formation (osteoblastic activity)
○ Patients are advised to take Bisphosphanates and Vitamin D

27
Q

Topical application

A

skin atrophy, ecchymosis, purple striae

28
Q

Other advserse effects of glucocorticoids

A

● Peptic ulcer
● increased susceptibility to infection
● inhibitory effect on the growth
plates in developing bone
● glaucoma
● cataract formation
● mood changes
● psychoses
● hypertension
● altered glucose metabolism
(hyperglycemia, insulin resistance
in DM patients)

29
Q

Therapeutic Uses and Diagnostic
Applications: Glucocorticoids

A

“ A single dose of glucocorticoid, even a large on, is virtually
without harmful effects, and a short course of therapy (up to 1
week), in the absence of specific contraindications, is unlikely to
be harmful. As the duration of glucocorticoid therapy is
increased beyond 1 week, there are time- and dose-related
increases in the incidence of disabling and potentially lethal
effects.”

30
Q

aromatase inhibitor; estrogen synthesis inhibitor

A

Aminoglutethimide

31
Q

selective inhibitor of CYP11B1: inhibits conversion of 11-deoxycortisol
to cortisol

A

Metyrapone

32
Q

Antifungal; in higher doses, an effective inhibitor of adrenal and
gonadal steroidogenesis by inhibiting 17a-hydroxylase

A

Ketoconazole

33
Q

antineoplastic drug; adrenocorticolytic agent used to treat inoperable
adrenocortical carcinoma

A

Mitotane

34
Q

● Aldosterone
● maintains fluid and electrolyte balance
● kidneys: increase sodium and water reabsorption and potassium excretion
● Aldosterone release is regulated by fluid and electrolyte status in the body
● can also be produced by the brain, heart, and other tissues

A

Mineralocorticoids

35
Q

● Angiotensin II: primary stimulus for aldosterone release as part of the reninangiotensin
system concerned with maintaining BP; potent vasoconstrictor
● Elevated potassium: serves as a stimulus to increase aldosterone release
● ACTH may also play a role in aldosterone release

A

Regulation of Secretion of Mineralocorticoids

36
Q

Aldosterone MOA

A

Mineralocorticoids increase sodium reabsorption by affecting
sodium channels and sodium pumps on the epithelial cells
lining the renal tubules
1. Aldosterone enters the cell and binds to a cytosolic
receptor = hormone-receptor complex
2. A-R complex travels to the cell’s nucleus, where it
induces mRNA synthesis
3. mRNA units undergo translation in the cytosol
4. proteins synthesized increase membrane permeability
to sodium
5. Na enters the cell from the lumen down an
electrochemical gradient (passive)
6. Na is ACTIVELY reabsorbed into the body and K is
actively secreted by the Na-K pump

37
Q

● Excess production of aldosterone
● can initially present as mild or severe to refractory hypertension
● can often go undiagnosed

A

Hyperaldosteronism

38
Q

○ Primary: tumor in the gland itself (Conn Syndrome) or bilateral adrenal
hyperplasia, other rare tumors
○ Secondary: due to excessive activation of the RAAS which can be due to
a renin-producing tumor, renal artery stenosis, or edematous d/o(Left
sided heart failure, pregnancy, cor pulmonale, or cirrhosis with ascites

A

Hyperaldosteronism etiology

39
Q

○ Surgery, adrenalectomy
○ Non-surgical: Mineralocorticoid receptor antagonists (MRAs)
○ ACEi and ARB to control BP
○ salt restriction

A

Hyperaldosteronism Tx/Mx

40
Q

As replacement therapy when natural production of mineralocorticoid is
impaired (Addison dse., post adrenalectomy)

A

Mineralocorticoid drugs / aldosterone agonists

41
Q

○ primary aldosterone-like agent for replacement therapy
○ chemically classified as a glucocorticoid but has high levels of
mineralocorticoid activity

A

Fludrocortisone

42
Q

Mineralocorticoid drugs / aldosterone
agonists adverse effects

A

hypertension, peripheral edema, weight gain, hypokalemia

43
Q

● Spironolactone
● Eplerenone

A

Mineralocorticoid Antagonists

44
Q

Eplerenone

A

○ competitive antagonists - they bind to
the receptor but do not activate it;
prevent aldosterone from binding with
renal cells and other tissues
○ increased sodium and water excretion
and decreased potasssium excretion
(“potassium sparing diuretics”)
○ Administered as diuretics, in treating
hypertension and heart failure
○ Spironolactone is also used to
diagnose hyperaldosteronism

45
Q

● Spironolactone
● Eplerenone

A

○ Adverse effects: hyperkalemia
○ Spironolactone may interfere with
endogenous sex hormones
(increased body hair, deepening of
voice, decreased libido, menstrual
irregularities, gynecomastia in men
○ GI disturbances
○ Spironolactone CNS effects
(drowsiness, lethargy, confusion,
headache

46
Q
A