Hyperprolactinaemia Flashcards
What is hyperprolactinaemia?
It is the most common hormonal disturbance of the pituitary gland.
How does hyperprolactinaemia present in men vs women?
It presents earlier in women with menstrual disturbance and later in men with erectile dysfunction and/or mass effects
What is the role of prolactin?
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
What secretes and inhibits prolactin?
Anterior pituitary secretes prolactin
Dopamine from the hypothalamus inhibits prolactin
What causes raised plasma prolactin?
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
What are the physiological causes of raised plasma prolactin ?
Pregnancy
Breastfeeding
Stress
Acute rise post-orgasm
Which drugs can lead to raised plasma prolactin?
Metoclopramide Haloperidol Methyldopa Oestrogens Ectasy/MDMA Antipsychotics
Which diseases can lead to raised plasma prolactin?
Prolactinoma Stalk damage Pituitary adenoma Surgery Trauma Tumours Hypothalamic disease
What are the symptoms of hyperprolactinaemia in women?
Women: Amenorrhoea or Oligomenorrhoea Infertility Galactorrhoea Decreased libido Anorgasmia Dry vagina Weight gain Late --> osteoporosis or local pressure effects of the tumour
What are the symptoms of hyperprolactinaemia in men?
Erectile dysfunction
Decreased facial hair
Galactorrhoea
Late –> osteoporosis or local pressure effects of the tumour
How would you diagnose hyperprolactinaemia?
Tests:
Basal prolactin blood test between9am - 4pm
Pregnancy test
TFT
U&Es
MRI pituitary if other causes are ruled out
How is hyperprolactinaemia managed?
Refer to specialist endocrinology clinic
Dopamine agonists:
- Bromocriptine
- Cabergoline
What is a microprolactinoma?
A tumour less than 10mm in size on MRI
How is a microprolactinoma managed?
Bromocriptine
- 1.25mg PO, increase weekly by 1.25mg intil 2.5mg/12 hour
Transphenoidal surgery is 2nd line treatment
How does bromocriptine work?
It is a dopamine agonist
It decreases prolactin secretion, restores menstrual cycles and decreases tumour size
What are the side effects of bromocriptine?
Nausea
Depression
Postural hypotension (minimise by giving at night)
Fibrosis
What are the side effects of carbogaline?
Fibrosis
Whay is transphenoidal surgery used as second line treatment?
It has a high sucess rate but there are risks of permanent hormone deficiency and prolactinoma recurrence
What is a macroprolactinoma?
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
How are macroprolactinomas treated?
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
How are macroprolactinomas managed surgically?
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
Why do pregnant women need to be monitored with prolactinomas?
There is an increased risk of tumour expansion
