Hyperprolactinaemia Flashcards
PRL effect
stimulates milk production in women
PRL control
the only hormone that is under suppresive control - inhibited by dopamine release from the hypothalamus
how does hyperprolactinaemia present
earler in women (menstrual disturbance) but later in men (eg with erectile dysfunction)
raised levels lead to hypogonadism, infertility and osteoperosis,by inhibiting secretion of gonadotropin releasing hormone
physiological causes of raised PRL
breast feeding
pregnancy
stress
sleep
drugs causing raised PRL
dopamine antagonists eg metaclopramide
antipsychotics eg phenothiazines
pathological causes of raised PRL
hypothyroidism - excessive TRH stimulates PRL (and TSH)
stalk lesions (prevent D from travelling from hypothalamus to pituitary gland) - iatrogenic, road accident
prolactinoma - PRL secreting pituitary tumour
female presentation
early
galactorrhoea
amenorrhoea
oligomenorrhoea
infertility
male presentation
late
classically, impotence
visual field abnormal
headache
how does hyperprolactinaemia cause impotence
raised PRL lowers testosterone levels
how can hyperprolactinaemia present later
osteoperosis
- increased bone resorption and BMD loss
prolactinoma investigations
prolactin concentration
MRI of pituitiary (micro and macro prolactinoma, pituitary stalk and optic chiasma)
visual fields (bitemporal hemianopia)
pituitary function tests (to see if other hormones are affected)
diameter definition between micro and macro prolactinoma
micro <1cm
macro > 1cm
medical treatment of hyperprolactinaemia
dopamine agonists are first line eg Cabergoline
what is the brand name for Cabergoline
Dostinex
side effects of Cabergoline
few
nausea, headaches
