Home | | Medicine Study Notes | Prolactinaemia

Chapter: Medicine Study Notes : Endocrine and Electrolytes


PRL has pulsitile and diurnal pattern: rises dramatically during sleep



·        Physiology:

o   PRL has pulsitile and diurnal pattern: rises dramatically during sleep

o   Dopamine inhibits prolactin

o   PRL is raised by: 

§  Oestrogen ® slightly ­PRL (ie women higher than men)

§  TRH ® slightly ­PRL (used in pituitary stimulation test)

§  T5 Dermatome stimulation ® ­PRL (but breastfeeding won‟t increase the size of a prolactinoma)

§  PRL rises through pregnancy 

§  Drugs: most major tranquillisers (ie antipsychotics), Metoclopramide (Maxolon) therapy for nausea blocks dopamine ®­PRL. Aldomet (alpha-methylDOPA) is the only hypotensive agent which increases prolactin (via dopamine depletion)

§  Can rise due to emotional or physical stress (including stressful venipuncture ® artefact)

§  High in chronic renal failure

§  Hypothyroidism ® ­TRH ® ­PRL

§  Sarcoidosis

§  Post-pill amenorrhoea (if due to other causes usually resolves < 1 year)

o   PRL level is not effected by Progesterone or nausea

·        Most common pituitary presentation.  Presents early in women (amenorrhoea), late in men

·        Symptoms:


o   Women: ¯libido, weight gain, apathy, vaginal dryness (due to hypooestrogen), amenorrhoea (very sensitive to ­PRL, infertility due to ­PRL ® ¯LH peak, ­PRL suppresses progesterone), galactorrhoea (will need to differentiate from breast inflammatory exudate – clear or green). If infertility, always check the man (cause of 1/3 of problems of infertility)


o   Men: impotence, ¯libido, reduced facial hair, local pressure effects, galactorrhoea (30%), mildly ¯testosterone (but asymptomatic). Not gynaecomastia (usually only in ¯testosterone or ­oestrogen)


·        Investigations: basal prolactin between 10.00 – 12.00 h (repeat 2 – 3 times), CT, MRI, assess pituitary function

·        Management:


o   If tumour < 10 mm (unlikely to be seen on Xray): bromocriptine to restore fertility avoids complications of ¯oestrogen due to ­PRL (could take pill instead). May ® postural hypotension. Commence slowly otherwise nausea. Good prognosis. No known teratogenic effects of bromocriptine – but still withdrawn on becoming pregnant if possible

o  Treat macroadenoma with surgery if bromocriptine fails to reduce size of PRL. But if pressure effects or pregnancy is contemplated then surgery. Monitor PRL


·        Prolactin deficiency causes failure of lactation but has no other know ill effects.  Deficiency is very rare


Study Material, Lecturing Notes, Assignment, Reference, Wiki description explanation, brief detail
Medicine Study Notes : Endocrine and Electrolytes : Prolactinaemia |

Privacy Policy, Terms and Conditions, DMCA Policy and Compliant

Copyright © 2018-2023 BrainKart.com; All Rights Reserved. Developed by Therithal info, Chennai.