Hyperprolactinemia Overview

Hyperprolactinemia is a state characterized by high levels of a hormone called prolactin in the blood. Prolactin is produced by the pituitary gland and plays a vital role in the development of the breasts during pregnancy.

While hyperprolactinemia is considered perfectly normal during pregnancy and breastfeeding, it can occur at other times due to disease and medication use. Hyperprolactinemia can affect both women and men, resulting in irregular menstrual periods and erectile dysfunction, among other things.

Prolactin levels may be elevated for any number of reasons. One of the more common causes is the formation of a benign tumor on the pituitary gland. This noncancerous growth, known as a prolactinoma, directly secretes excessive prolactin while decreasing the levels of other sex hormones.

Diseases affecting a portion of the brain called the hypothalamus can also cause hyperprolactinemia. The hypothalamus functions as the link between the nervous system and the pituitary gland. The increase in prolactin levels can often be directly linked to a tumor, trauma, or infection of the hypothalamus.

Other causes may include:

• Hypothyroidism (low thyroid hormone levels)
• Cirrhosis of the liver
• Chronic kidney failure
• Antidepressants (Anafranil, Norpramin)
• Antipsychotics (Haldol, Zyprexa, Risperdal)
• Antihypertensives (Verelan, Calan, Covera-HS, Isoptin)
• Antinauseals (Reglan, Primperan, Lexapram)
• Acid H2 blockers (Tagamet, Zantac)
• Estrogen

The symptoms of hyperprolactinemia in women can vary. When occurring outside of pregnancy or breastfeeding, they may include:

• Infertility
• Gallactorrhea (abnormal lactation)
• Infrequent or irregular periods
• Amenorrhea (disappearance of ovulation periods)
• Loss of libido
• Breast pain
• Painful intercourse due to vaginal dryness

When occurring in men, the symptoms typically involve sexual dysfunction and/or pain associated with the formation of the prolactinoma. Common signs and symptoms include:

• Erectile dysfunction
• Gynecomastia (development of breast tissue)
• Lactation
• Infertility
• Loss of libido

The diagnosis of hyperprolactinemia involves a routine blood test to check prolactin levels. If the blood levels are elevated, the doctor may want to repeat the test, this time after fasting for at least eight hours. Normal prolactin levels are less than 500 mIU/L for women and less than 450 mIU/L for men.

A magnetic resonance imaging (MRI) scan may be ordered to look for evidence of a pituitary growth or for damage to surrounding tissues. Blood tests to evaluate other hormone levels may be useful in ruling out any other possible causes of the symptoms.

The goal of treatment is to return prolactin to normal levels. There are a number of standard options to achieve this:

• The medications Parlodel (bromocriptine) and Dostinex (cabergoline) are known to be effective in reducing prolactin levels and shrinking pituitary tumors.
• Surgery may sometimes be used to remove a pituitary tumor if the medications are not working or are poorly tolerated.
• Radiation, while rarely used, may be suggested if the medicines and surgery have not been effective.
• Hypothyroidism can be treated with synthetic thyroid hormone, which should bring prolactin levels down.
• If high prolactin levels are caused by prescription drugs, substitute medications may be prescribed.