Hyperprolactinaemia

Question 1

What is the function of prolactin

Answer 1

1. Stimulates lactation and breast development
2. Inhibit GnRH synthesis - inhibits ovulation in females + spermatogenesis in males (decreases FSH/LH as a response)
3. Increase dopamine secretion

Question 2

Explain the relationship between prolactin and dopamine

Answer 2

dopamine inhibits prolactin

Question 3

What secretes prolactin?

Answer 3

anterior pituitary

Question 4

what do raised prolactin levels lead to?

Answer 4

hypogonadism
infertility
osteoporosis (hence ↓LH/FSH and ↓testosterone or oestrogen)

Question 5

What level is a raised prolactin?

Answer 5

> 390mu/L

Question 6

What are causes of hyperprolactinaemia?

Answer 6

1. XS production from pituitary e.g. prolactinoma
2. Disinhibition by compression of the pituitary stalk reducing local dopamine levels
3. dopamine antagonists

Question 7

Give physiological causes of raised prolactin

Answer 7

pregnancy
breastfeeding
stress

Question 8

What drugs cause raised prolactin?

Answer 8

metoclopramide
haloperidol
methyldopa
oestrogens 
ecstasy
antipsychotics

Question 9

What diseases cause raised prolactin?

Answer 9

Prolactinoma
Stalk damage - pituitary adenomas, surgery, trauma
Hypothalamic disease - craniopharyngioma
Other: hypothyroidism, chronic renal failure

Question 10

What are the sx of hyperprolactinaemia in females?

Answer 10

1. amenorrhoea/oligomenorrhoea
2. infertility
3. galactorrhoea
4. ↓libido, ↑weight, dry vagina.

Question 11

What are the sx of hyperprolactinaemia in men/

Answer 11

ED
↓facial hair
Galactorrhoea
May present late with osteoporosis or local pressure effects from the tumour

Question 12

What are the tests for hyperprolactinaemia?

Answer 12

Basal PRL
LFTs
U&Es
Pregnancy test 
MRI pituitary

Question 13

What is the treatment of prolactinoma?

Answer 13

1. Dopamine agonists - cabergoline, bromocriptine

2. Surgery - trans-sphenoidal (if cannot tolerate or fail to respond to medical therapy)