Hyperprolatinaemia Flashcards
What normal conditions would cause high prolactin in blood?
- Pregnancy
- Lactation
- Severe stress
What are prolactinomas?
- prolactin-producing tumours of the pituitary gland
What is the physiology of prolactin?
- Produced by lactotroph cells of APG
- Under inh. control of dopamine
What stimulates prolactin production?
- dopamine receptor antagonists
- thyrotropin-releasing hormone (TRH)
- vasoactive intestinal peptide (VIP) or epidermal growth factor
- suckling by an infant
What extra pituitary glands produce prolactin too?
- adipose tissue
- immune cells
- hair follicle
What are the effects of raised prolactin?
*think in women and men
Women
- inhibits gonadotrophin secretion- FSH and LH
- menstrual dysfunction & galactorrhoea
Men
- direct, reversible effect on the hypothalamus
- secondary hypogonadism
- reduced libido and erectile dysfunction
What are the common causes of hyperprolactinemia?
- Prolactinoma
- Hypothyroidism
- Antipsychotics
What are the causes of hyperprolactinaemia?
*think physiological, intracranial, endocrine, drugs
Physiological
- Pregnancy
- Puerperium
- breast stimulation
Intracranial
- Pituitary tumours
- Head injury - disrupting pituitary stalk
- Brain surgery
- Post ictal
Endocrine
- Hypothyroidism
- Cirrhosis
- Cushings
- Polycystic Ovary syndrome
Drugs
- Dopamine receptor antagonist (Domperidone, metoclopromide)
- Dopmaine depleting agents (methyldopa)
- Antidepressant (TCA, MOA inh. SSRI)
What are the prolactinoma classification?
- Microadenomas: <10 mm. (very common)
- Macroadenomas: >10 mm.
- Giant pituitary adenomas: >40 mm. (more common in men than women)
- Malignant prolactinomas (very rare)
What is the most common hormone secreting pituitary tumour?
- Prolactinoma
What are the clinical presentation of hyperprolactinaemia?
*think women, men, children, and tumour size
Women
- amenorrhoea
- galactorrhoea
- infertility
- low libido
Men
- low libido
- erectile dysfunction
- reduced beard growth
- gynaecomastia
Child
- delayed puberty
Tumour size
- Headache\bitemporal heminopia
- cranial nerve palsies
- hypopituitarism
What Ix would you order for Hyperprolactinaemia?
- TFTs
- exclude pregancy
- serum prolactin
- *venepuncture can increase prolactin
Further testing
- Visual field
- MRI
- Assess pituitary function
How would you mx hyperprolactinaemia?
- Asymptomatic with hyperprolactinaemia +/- prolactinoma
- No Tx
- Majority of tumour x inc. size
- Dopamine agonist
- Cabergoline
- Bromocriptine
- If DA ineffective
- Surgery
When should prolactinomas be treated?
- Adverse effects of tumour size.
- Adverse effects of hyperprolactinaemia.
What precautionary measures to take when administering Dopamine Agonist?
Exclude
- cardiac valve fibrosis
- pulmonary fibrosis
