Management of Hyperprolactinaemia

Abstract

Excessive prolactin secretion is a not infrequent cause of anovulation and consequent infertility, often associated with amenorrhea or oligomenorrhea. Only hyperprolactinaemia causing ovulatory disturbance deserves treatment. Clinically, galactorrhea may be a sign of hyperprolactinaemia but galactorrhea may often occur without associated hyperprolactinaemia and vice-versa. Oligo/amenorrhea is a more important symptom which demands a serum prolactin estimation. Any disruption in the hypothalamic-pituitary pathway, (e.g. dopamine reducing medications, space occupying lesions) will raise prolactin concentrations and if these reach a certain level, ovulatory dysfunction will result. A further cause of hyperprolactinaemia is a prolactin-secreting tumour (prolactinoma) of the anterior pituitary which is autonomous in nature and may be a micro or a macroadenoma. Hypothyroidism is a further possible cause of hyperprolactinaemia as thyroid releasing hormone, secreted by the hypothalamus as a compensatory mechanism, has the property of prolactin release from the pituitary. The work-up following the finding of hyperprolactinaemia associated with oligo- or anovulation should include neuro-radiological visualization of the hypothalamic pituitary region by MRI or CT to look for a micro- or macroadenoma, empty sella syndrome or a para-sellar tumour. Serum TSH, FSH and LH should also be estimated. Visual disturbances associated with a visualized tumour should also prompt an examination of visual fields. A pituitary tumour impinging on the optic chiasma characteristically causes a bitemporal hemianopia. When hyperprolactinaemia and anovulatory infertility are associated with medication, the benefits and disadvantages of reducing dosage or withdrawing medication must be carefully weighed up. Hypothyroidism as a cause should be treated with the appropriate medication for correction of thyroid function rather than with specific prolactin-lowering agents. Many dopamine agonists are in use for the treatment of infertility associated with hyperprolactinaemia: bromocriptine carbergoline, quinagolide