Hyperprolactinaemia

Question 1

What is hyperprolactinaemia?

Answer 1

It is the most common hormonal disturbance of the pituitary gland.

Question 2

How does hyperprolactinaemia present in men vs women?

Answer 2

It presents earlier in women with menstrual disturbance and later in men with erectile dysfunction and/or mass effects

Question 3

What is the role of prolactin?

Answer 3

It inhibits lactation and inhibits secretion of gonadotropin releasing hormone.

This leads to decreased LH, FSH, testosterone and oestrogen.

Raised levels therefore stimulate hypogonadism, infertility and osteoporosis

Question 4

What secretes and inhibits prolactin?

Answer 4

Anterior pituitary secretes prolactin

Dopamine from the hypothalamus inhibits prolactin

Question 5

What causes raised plasma prolactin?

Answer 5

1) Excess production from the pituitary eg. prolactinoma
2) Disinhibition, by compression of the pituitary stalk, thus reducing local dopamine levels
3) Use of dopamine antagonist

Question 6

What are the physiological causes of raised plasma prolactin ?

Answer 6

Pregnancy
Breastfeeding
Stress
Acute rise post-orgasm

Question 7

Which drugs can lead to raised plasma prolactin?

Answer 7

Metoclopramide
Haloperidol
Methyldopa
Oestrogens
Ectasy/MDMA
Antipsychotics

Question 8

Which diseases can lead to raised plasma prolactin?

Answer 8

Prolactinoma
Stalk damage 
Pituitary adenoma
Surgery
Trauma
Tumours
Hypothalamic disease

Question 9

What are the symptoms of hyperprolactinaemia in women?

Answer 9

Women:
Amenorrhoea or Oligomenorrhoea
Infertility
Galactorrhoea
Decreased libido
Anorgasmia
Dry vagina
Weight gain
Late --> osteoporosis or local pressure effects of the tumour

Question 10

What are the symptoms of hyperprolactinaemia in men?

Answer 10

Erectile dysfunction
Decreased facial hair
Galactorrhoea
Late –> osteoporosis or local pressure effects of the tumour

Question 11

How would you diagnose hyperprolactinaemia?

Answer 11

Tests:
Basal prolactin blood test between9am - 4pm
Pregnancy test
TFT
U&Es
MRI pituitary if other causes are ruled out

Question 12

How is hyperprolactinaemia managed?

Answer 12

Refer to specialist endocrinology clinic
Dopamine agonists:
- Bromocriptine
- Cabergoline

Question 13

What is a microprolactinoma?

Answer 13

A tumour less than 10mm in size on MRI

Question 14

How is a microprolactinoma managed?

Answer 14

Bromocriptine
- 1.25mg PO, increase weekly by 1.25mg intil 2.5mg/12 hour

Transphenoidal surgery is 2nd line treatment

Question 15

How does bromocriptine work?

Answer 15

It is a dopamine agonist

It decreases prolactin secretion, restores menstrual cycles and decreases tumour size

Question 16

What are the side effects of bromocriptine?

Answer 16

Nausea
Depression
Postural hypotension (minimise by giving at night)
Fibrosis

Question 17

What are the side effects of carbogaline?

Answer 17

Fibrosis

Question 18

Whay is transphenoidal surgery used as second line treatment?

Answer 18

It has a high sucess rate but there are risks of permanent hormone deficiency and prolactinoma recurrence

Question 19

What is a macroprolactinoma?

Answer 19

A tumour >10mm diameter on MRI

They are near the optic chaism so may lead to pther specific symptoms such as decrease visual acuity, diplopia, opthalmoplegia, visual-field loss and optic atrophy

Question 20

How are macroprolactinomas treated?

Answer 20

Dopamine agonist (bromocriptine if fertility is the goal)

Surgery is rarely needed but consider if visual symptoms or pressure effects which fail to respond to medical treatment

Question 21

How are macroprolactinomas managed surgically?

Answer 21

Resect the tumour - usually cannot resect all

Post-op follow up with bromocriptine and radiotherapy as the surgery does not usually resect the entire tumour

Question 22

Why do pregnant women need to be monitored with prolactinomas?

Answer 22

There is an increased risk of tumour expansion