Hyperprolactinaemia its physiology ,etiology ,clinical picture,investigation and newest treatment

1. Physiology :

a. Hormone : Prolactin.

b. Gland : Pituitary gland [anterior lobe].

c. Function of the hormone :

i. Necessary for lactation.

ii. ↓↓ GnRH.

d. Regulation of this hormone :

i. ↑ prolactin :

_ PRH ( prolactin releasing hormone.)?

_ Recently it’s thought that TRH ( thyrotropin

releasing hormone ) is a prolactin releasing hor.

ii. ↓ prolactin :

_ PRIH ( prolactin release inhibiting hor.)

→ dopamine.

2. Etiology :

a. Physiological : pregnancy , lactation , stress,

sleep & nipple stimulation.

b. Drugs :

i. Dopamine antagonist : phenothiazines.

ii. Dopamine depletors : methyl-dopa & reserpine.

c. Diseases of many organs :

i. Pituitary :

1. tumors : prolactinoma.

2. diseases : grnuloma & sarcoidosis.

ii. Thyroid : 1ry hypothyroidism →↑ TRH→ ↑ prolactin.

iii. Renal : CRF → ↓ prolactin clearance.

iv. Liver cirrhosis : → ↓ metabolism.
3. C / P :

a. C / p of i cause :

i. Tumor.

ii. Dopamine antagonist.

iii. Liver cirrhosis or CRF.

b. C / p of i hormone :

i. ♀ :

1. glactorrhea.
2. amenorrhea.

3. osteoprosis (due to estrogen deficiency).

ii. ♂ :

1. impotence.

2. loss of libido.

3. infertility.

4. gynaecomastia.

5. never glactorrhea.

4. Investigation :

a. Inv. for i cause :

i. Imaging for i gland :

1. U/S.

2. C.T. & M.R.I.

ii. Liver & renal function tests.

b. Assay of i hormone level :

Prolactin > 300 n.gm/ml → suggestive of

[ n < 20 ng / ml ]. pituitary adenoma.

c. Inv. of i function of i hormone :

i. Glactorrhea.

ii. Infertility.

iii. Pressure manifestations.

5. Treatment :

a. Dopamine agonist :

i. Bromocriptine : dose 1.25 mg at bed time

↑ gradually to 15 mg/day.

ii. Cabergoline : drug of choice →less side effects.

b. Surgery: trans-sphenoidal or

trans-cranial → removal of i tumor.

c. Irradiation : proton or _ particles.
see the pictures

d. TTT of i cause : e.g. : myxoedema.