Brainscape's Knowledge GenomeTM

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


See full index

Endocrine > pituitary lecture 1 and 2 > Flashcards

pituitary lecture 1 and 2 Flashcards

1
Q

what would class a tumour as a microadenoma?

A

tumour that is 1 cm or less

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

what would class a tumour as a macroadenoma?

A

if the tumour is greater than 1 cm

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

what are physiological causes for raised prolactin?

A
  • breast feeding
  • pregnancy
  • stress
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what drugs may raise prolactin?

A
  • dopamine antagonists e.g. metoclopramide
  • antipsychotics e.g. phenothiazines
  • antidepressants eg TCA, SSRIs
  • Other: oestrogen, cocaine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what investigations would you do if you suspected prolactinoma?

A
  • serum prolactin (would be high)
  • MRI pituitary (would be too big)
  • check visual fields (for bitemporal hemianopia)
  • pituitary function tests (to see if other hormones are affected, in microprolactinoma it is unlikely to affect them but macroprolactinoma might)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what treatment is given for prolactinoma?

A

USE DOPAMINE AGONISTS!!

-Cabergoline (Dostinnex) is usually used due to least side effects, it is given once to twice per week orally

Other dopamine agonists:

  • bromocriptine (3x per day orally)
  • quinagolide (1x per day orally)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what are side effects of dopamine agonists?

A
  • nausea/vomiting
  • low mood
  • fibrosis of heart valves/ retroperitoneal (however patients who are on meds for prolactinoma have such low dosage they wont experience this)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what effects do dopamine agonists have on prolactinoma?

A
  • normalise prolactin levels

- tumour shrinkage

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

what causes acromegaly?

A

GH excess

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

how does acromegaly present?

A
  • bones increase in size
  • thickened soft tissues (skin, large jaw, sweaty, large hands)
  • snoring/ sleep apnoea (due to thickened nasopharynx)
  • hypertension
  • cardiac failure
  • headaches
  • DM
  • Hypopituitarism
  • Visual field disturbances
  • early CV death
  • colonic polyps and colonic cancer
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

how is acromegaly diagnosed?

A

Gold standard= GTT suppression test, give 75g oral glucose and check GH every half hour for 2 hours, normally GH < 0.4 mg/l so if it doesn’t do this it suggests acromegaly

Blood serum:
-increased IGF1 (sometimes it is not that raised so dont always use this test)

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

what investigations should be done if there’s suspected acromegaly?

A
  • GTT suppression test, if GH> 0.4mg/l then acromegaly is present
  • check visual fields
  • CT or MRI pituitary gland
  • pituitary function test (to check the other hormones)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is the treatment for acromegaly?

A

PITUITARY SURGERY = first line (90% cure if microadenoma and 50% cure if its macroadenoma)

DRUGS= second line

  • Somatostatin analogues: Sandostatin and lanreotide
  • Dopamine Agonists: Cabergoline (only works in 10-15% of patients)
  • GH Antagonist: pegvisomant (most effective but expensive so last line)

-radiotherapy alone= third line (25% success at 3 years)

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

what are some examples of somatostatin analogues?

A
  • sandosatin LAR
  • lanreotide autogel
  • pasireotide LAR
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what effect do somatostatin analogues have on GH?

A

they reduce GH in most patients

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

what effect do somatostatin analogues have on the tumour?

A
  • they shrink the tumour (by 30-60%)

- however the tumour will re expand 6 weeks after stopping somatostatin analogues

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

how long does it take for somatostatin analogues to work?

A

6-12 months

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

what are side effects of somatostatin analogues?

A

-local stinging

Short term:

  • flatulence
  • diarrhoea
  • abdominal pain

long term:
-gall stones

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

what type of injection is Sandostatin LAR?

A

IM injection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what type of injection is pasireotide LAR?

A

IM injection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what type of injection is lanreotide autogel?

A

SC injection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what dose is Sandostatin LAR given?

A

1-30mg once a month

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

when would you choose to use a dopamine agonist in acromegaly?

A
  • sometimes patients with acromegaly secrete GH and prolactin
  • would use a dopamine agonist
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what is an examples of a GH antagonist?

A

pegvisomant

25
Q

how is pegvisomant administered?

A

SC injection 10-30mg per day

26
Q

what is the mechanism of action of GH antagonists?

A

-bind to GH receptor blocking GH activity

27
Q

what effect do GH antagonists have on tumour size?

A

-tumour size does not decrease, actually sometimes there is a small increase in tumour size

28
Q

are GH antagonists expensive?

A

yes very

29
Q

what is there excess of in cushings syndrome?

A

-cortisol

30
Q

what is the effect of excess cortisol on protein?

A

Protein loss

31
Q

what can protein loss cause?

A
  • myopthy (wasting)
  • osteoperosis (fractures)
  • thin skin (striae, bruising)
32
Q

what effect does excess cortisol have on carbohydrate/lipid metabolism?

A

-it alters carbohydrate/lipid metabolism causing high blood glucose

33
Q

what effect does cushings syndrome have on mineralcorticoid?

A

-it creates excess mineralcorticoid leading to hypertension and oedema

34
Q

what effect does cushings syndrome have on androgen?

A

-it causes excess androgen leading to virilism, hirsutism, ane and oligo/amenorrhoea

35
Q

how does chushings present?

A
  • thin skin
  • proximal myopathy
  • frontal balding in women
  • conjunctivital oedema
  • osteoperosis
36
Q

what tests are used for diagnosing Cushings?

A

Overnight 1mg dexamethasone supression test (oral):

  • cortisol <50nmol/l next morn= normal
  • cortisol > 130nmol/l next morn= abnormal

Urine free cortisol (24 hr urine collection)

  • total <250 is normal
  • cortisol/creatinine ratio of <25 is normal

Diurnal cortisol variation (midnight/8am)

  • loss of diurnal variation suspicious of Cushing’s
  • serum/saliva/ spot urine collection

Diagnostic test (low dose DST)

  • 2 day 2mg/day dexamthesone suppression test
  • cortisol <50 nmol/l 6 hours after last dose indicates no Cushings
  • cortisol >130nmol/l = cushings
37
Q

what is the difference between cushings disease and cushings syndrome?

A

cushings disease= tumour in the pituitary causing excess cortisol

cushings syndrome= tumour elsewhere causing excess cortisol

38
Q

what else apart from tumours in pituitary gland can cause cushings?

A
  • adenoma of the adrenal gland
  • ectopic ACTH production in thymus, lung or pancreas can cause Cushings
  • alcohol, depression and certain steroid hormones
39
Q

what would a low dexamethasone test show for cushings caused by pituitary tumour, adrenal adenoma or an ectopic tumour?

A

abnormal results

40
Q

what would ACTH levels be if someone had cushings caused by a pituitary tumour?

A

25-300

41
Q

what would ACTH levels be if someone had cushings caused by an adrenal tumour?

A

<1

42
Q

what would ACTH levels be if someone had cushings caused by an ectopic tumour?

A

> 300

43
Q

what would CRF (corticol releasing hormone/factor) test show in a patient with cushings caused by a pituitary tumour?

A

ACTH raised by 50%

Cortisol raised by 20%

44
Q

what would treatment for cushings caused by pituitary tumour?

A

-pituitary endoscopic surgery

45
Q

what would treatment for cushings caused by pituitary tumour?

A

first line= transphenoidal hypophysectomy
if it reaccurs= radiotherapy
if radiotherapy unsuccesful= bilateral adrenalectomy

46
Q

what would treatment for cushings caused by adrenal tumour?

A

first line=transphenoidal surgery
second line=
third line=

47
Q

what would treatment for cushings caused by adrenal tumour?

A

-adrenalectomy

48
Q

what would treatment for cushings caused by an ectopic tumour?

A

-remove source
OR
-bilateral adrenalectomy

49
Q

what drug treatment is given for cushings disease?

A

Metyrapone= if other treatment fails and while waiting for radiotherapy to work

Pasireotide LAR

Ketoconazole (not commonly used as hepatotoxic)

50
Q

what are side effects of Metyrapone?

A

nausea and vomiting are common

51
Q

why is Ketoconazole not commonly used to treat cushings?

A

-as its hepatotoxic

52
Q

what is pan hypopituitarism?

A

-a condition in which all production and synthesis of hormones in the pituitary gland is reduced

53
Q

what does absence of GH due to pan hypopituitarism cause?

A

-growth failure

54
Q

what does absence of TSH due to pan hypopituitarism cause?

A

-hypothyroidism

55
Q

what does absence of LH/FSH due to pan hypopituitarism cause?

A

-hypogonadism

56
Q

what does absence of ACTH due to pan hypopituitarism cause?

A

-hypoadrenal

57
Q

what does absence of posterior pituitary function due to pan hypopituitarism cause?

A

-diabetes insipidus

58
Q

what are the causes of hypopituitarism? (EDIT)

A
  • pituitary tumours
  • other local brain tumours
  • iatrogenic: surgery
  • granulomatous diseases: TB, histiocytes X, sarcoidosis
  • Vascular disease: polyarteritis

Endocrine (53 decks)

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