Prolactin and galactorrhoea

Microbiology

Prolactin is secreted by the anterior pituitary gland with release being controlled by a wide variety of physiological factors. Dopamine acts as the primary prolactin releasing inhibitory factor and hence dopamine agonists such as bromocriptine may be used to control galactorrhoea. It is important to differentiate the causes of galactorrhoea (due to the actions of prolactin on breast tissue) from those of gynaecomastia

Features of excess prolactin

men: impotence, loss of libido, galactorrhoea
women: amenorrhoea, galactorrhoea

Causes of raised prolactin

prolactinoma
pregnancy
oestrogens
physiological: stress, exercise, sleep
acromegaly: 1/3 of patients
polycystic ovarian syndrome
primary hypothyroidism (due to thyrotrophin releasing hormone (TRH) stimulating prolactin release)

Drug causes of raised prolactin

metoclopramide, domperidone
phenothiazines
haloperidol
very rare: SSRIs, opioids