The presence of abnormally high levels of prolactin in the blood is reffered to as Hyperprolactinaemia or hyperprolactinemia
Prolactin is a peptide hormone produced by the anterior pituitary gland that is primarily associated with lactation and plays a vital role in breast development during pregnancy. Hyperprolactinaemia may cause galactorrhea (production and spontaneous flow of breast milk) and disruptions in the normal menstrual period in women. Normal levels are less than 500 mIU/L [20 ng/mL or µg/L] for women. Prolactin lowers levels of sex hormones (estrogen and testosterone) in both men and women.
Hyperprolactinemia inhibits the secretion of gonadotropin-releasing hormone (GnRH) from the hypothalamus (by increasing the release of dopamine from the arcuate nucleus), which in turn inhibits the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from the pituitary gland and results in diminished gonadal sex hormone production (termed hypogonadism).
- Serum prolactin increases throughout pregnancy, reaching a peak at delivery.
- Nipple stimulation during breastfeeding increases serum prolactin concentrations, presumably via a neural pathway. The magnitude of the increase is directly proportional to the degree of preexisting lactotroph hyperplasia due to estrogen.
- Several drugs may determine a significant increase in prolactin serum concentration that is frequently associated with symptoms. The so-called typical antipsychotics are frequently responsible for drug-related hyperprolactinemia.
Effects of Hyperprolactinemia :
Both men and women with high prolactin levels may have infertility, low sex drive, and bone loss. Women may have:
- No menstrual periods or irregular periods
- Vaginal dryness, making sex painful
- Breast discharge when not pregnant or nursing
Adolescent girls may also have menstrual problems and breast discharge.
A blood test is used to measure the prolactin level. Most often, a single blood test is all that is needed. For most patients, a level below 25 μg/L (micrograms per liter) is normal, and above 25 is too high. A prolactin level above 250 μg/L most often indicates a prolactinoma. However, some drugs can cause levels to be that high.
Many other doctors will do other tests to look for the cause of excess prolactin. One cause is an underactive thyroid (hypothyroidism), so you may have a blood test to check your thyroid hormone levels. If the doctor thinks you may have a prolactinoma or other pituitary tumor, you likely will get an MRI (magnetic resonance imaging) scan of the brain and pituitary.
If you are a woman of childbearing age, your doctor will rule out pregnancy as a cause of elevated prolactin.
The line of treatment needs to be watched by your physician..
If your physician thinks a medication you are taking has caused the excess prolactin, the doctor may tell you to stop taking that medicine for at least 3 days. Do not stop taking your medicine unless your doctor instructs you to do so. After a time off the medicine, your doctor will order another blood test for prolactin, to see if the levels have returned to normal. If you cannot be off your medicine, your doctor will give you a similar drug that does not raise prolactin levels.
When no good substitute drug is available, your doctor may give you cabergoline or bromocriptine to lower prolactin production.