Cushing's Disease Flashcards Preview

Endo > Cushing's Disease > Flashcards

Flashcards in Cushing's Disease Deck (26)
Loading flashcards...
1
Q

what is Cushing’s syndrome

A
  • any excess cortisol state
2
Q

what is Cushing’s disease

A
  • Cushing’s syndrome due to ACTH producing pituitary adenoma
3
Q

causes of Cushing’s syndrome

A
  • Cushing’s disease (pituitary adenoma)
  • ectopic ACTH production
  • adrenal cortical adenoma
4
Q

Cushing’s syndrome due to pituitary ACTH producing tumor (Cushing’s disease)

hormone levels:
CRH:
ACTH:
cortisol:

size of the adrenal glands

treatment

A

hormone levels:
CRH: low (negative feedback)
ACTH: high
cortisol: high

  • hyperplastic
  • transphenoidal surgery
  • block ACTH secretion by the tumor or block steroid synthesis
5
Q

Cushing’s syndrome due to adrenal tumor making cortisol

hormone levels:
CRH:
ACTH:
cortisol:

treatment (successful for/not)

A

hormone levels:
CRH: low
ACTH: low
cortisol: high

  • surgery (successful for adenomas/not for carcinoma (cancer usually too invasive)
  • block steroid biosynthesis
6
Q

Cushing’s syndrome due to ectopic ACTH-producing tumor

hormone levels:
CRH:
ACTH:
cortisol:

what will pituitary ACTH levels be

treatment

A
  • hormone levels:
    CRH: low
    ACTH: high
    cortisol: high
  • pituitary ACTH levels will be low
  • find malignancy and remove (surgery, radiation)
  • block steroid biosynthesis
7
Q

glucocorticoid excess features of Cushing’s syndrome

A
  • muscle wasting
  • easy bruising or poor wound healing
  • osteoporosis or fractures
  • central obesity
  • glucose intolerance, hyperglycemia
  • psychiatric disturbances
8
Q

what symptoms are present in most cases of cortisol excess

A
  • psychiatric disturbances

- metabolic alkalosis

9
Q

mineralocorticoid excess symptoms in Cushing’s syndrome

A
  • salt retention, hypertension, edema
  • hypokalemia
  • metabolic alkalosis
  • excess cortisol cross-reacts with aldosterone/androgen receptors (mineralocorticoid) producing these symptoms
10
Q

androgen excess symptoms in Cushing’s syndrome

why do you get androgen symptoms

A
  • hirsutism, acne
  • amenorrhea
  • excess cortisol cross-reacts with aldosterone/androgen receptors producing these symptoms
11
Q

steps in evaluating Cushing’s syndrome

A
  1. confirm hypercortisolism

2. localize source by measuring ACTH

12
Q

how do you confirm hypercortisolism

A
  • 24 hour urinary free cortisol
  • low-dose demethasone suppression test
  • salivary free cortisol
13
Q

normally demethasone suppression test suppresses cortisol to what level

A

< 1.8 mcg/dL

14
Q

watch out for demethasone suppression test in patients taking what

A
  • estrogen containing birth control
15
Q

in localizing the source, ACTH will be high when

ACTH will be low when

A
  • ACTH-dependent Cushing’s

- ACTH-independent Cushing’s

16
Q

if ACTH dependent, must differentiate between

how do you do this

which will respond

how much do you give

level to know it responds

A
  • pituitary and ectopic ACTH
  • high dose dexamethasone suppression test
  • inferior petrosal sinus sampling test
  • pituitary ACTH will respond and decrease
  • 8 mg dexamethasone
  • cortisol suppression by 50% or < 5 mcg/L
17
Q

if ACTH independent, what is the source

what do you do

usual cause (benign/malignant)

size

A
  • adrenal gland
  • adrenal imaging
  • adrenal adenoma (benign)
  • contralateral side is atrophic due to decreased ACTH
18
Q

MOA of mifepristone in treating hypercortisolism

A
  • inhibits glucocorticoid receptors
19
Q

MOA of spironolactone in treating hypercortisolism

A
  • inhibits mineralocorticoid receptors
20
Q

MOA of ketoconazole in treating hypercortisolism

importance of this drug

A
  • inhibits steroidogenesis

- rapid onset of action

21
Q

MOA of aminoglutethimide in treating hypercortisolism

A
  • inhibits steroidogenesis
22
Q

MOA of Cabergoline and Pasireotide in treating hypercortisolism

A
  • decreased ACTH secretion by tumor
23
Q

factors determining the severity of glucocorticoids causing Cushing’s syndrome

A
  • effective dose (lowest dose you can give)
  • how long the drug acts
  • duration of treatment (shorter is better)
  • tissue distribution (stay localized if you can with topical)
  • AVOID ANTI-INFLAM AND IMMUNOSUPPRESANT DRUGS IF YOU CAN
24
Q

between hydrocortisone, prednisone, and dexamethasone, which has the longest half life

A
  • dexamethasone
25
Q

the problem of long term adrenal suppression

A
  • ACTH must recover

- cortisol recovery takes a long time! (almost a year)

26
Q

what discontinuing long term steroid therapy, what is important to do

A
  • gradually taper down the dose