Synopsis
Confirm biologically relevant prolactin excess, distinguish medicine, pregnancy, systemic and stalk causes from prolactinoma, and deliver safe dopamine-agonist, visual, fertility and pregnancy care.
- Hyperprolactinaemia suppresses pulsatile GnRH, reducing LH and FSH and causing amenorrhoea, anovulation, infertility, low libido, erectile dysfunction and bone loss; galactorrhoea is neither necessary nor specific.
- Before calling a pituitary tumour, exclude pregnancy, primary hypothyroidism, renal or hepatic disease, chest-wall stimulation and medicines such as antipsychotics, metoclopramide, domperidone, opioids and some antidepressants.
- Repeat a modest prolactin under calm sampling conditions and ask the laboratory about macroprolactin when symptoms and result disagree; venepuncture stress can raise the concentration.
Key red flags
Acute severe headache, visual loss, ophthalmoplegia or reduced consciousness suggests pituitary apoplexy and requires emergency cortisol and neurosurgical management.
Investigation priorities
Confirm persistence and judge the magnitude under conditions that minimise transient stress elevation.
Management branches
A laboratory concentration is above the reference range without an established prolactinoma.
- Check pregnancy, symptoms, stress, breast or chest stimulation, thyroid, renal and hepatic function and every relevant prescription or recreational drug.
- Repeat modest elevations and request macroprolactin evaluation when biology and concentration do not align.
Key medicines
CabergolineThe current SmPC starts hyperprolactinaemia treatment at 0.5 mg weekly in one or two doses, with gradual specialist titration to response.
BromocriptineUse a low starting dose with food and increase slowly under the current BNF regimen when cabergoline is unsuitable or a pregnancy pathway favours it.