The most commonly-used medications for prolactinoma are dopamine agonists. These medications are usually taken by mouth, and they have effects similar to dopamine, a naturally-occurring chemical that regulates certain hormones in the body. When these drugs are taken by people with prolactinoma, they help lower the levels of prolactin in the body and may help shrink the tumor. Common medications used include bromocriptine and cabergoline. However, these drugs only work while they're being taken, so most people must take the medication several times a day for a long period of time.
A Answers (2)
Honor Society of Nursing (STTI) answered
Jack Merendino, MD, Endocrinology, Diabetes & Metabolism, answered
Medications such as bromocriptine (brand name Parlodel) and cabergoline (brand name Dostinex) work by mimicking the action of dopamine in the pituitary gland. Normally, nerve cells in the hypothalamus control prolactin release. The hypothalamus is a small part of the brain situated above the pituitary gland. Nerve cells in the hypothalamus release chemicals into blood vessels which connect the hypothalamus to the pituitary. These chemicals in turn control the release of various pituitary hormones, including growth hormone, ACTH, FSH, LH, TSH and prolactin. The main chemical regulating prolactin release is dopamine. Dopamine made by nerve cells in the hypothalamus prevents the release of prolactin.
Many medications, especially those used for the treatment of schizophrenia and other serious psychiatric illness, work by blocking the effect of dopamine throughout the brain. This has favorable effects on mood and helps reduce hallucinations, but in the pituitary gland it increases prolactin levels since the inhibitory effect of dopamine on prolactin release is reduced. If there is damage to the hypothalamus or to the blood vessels connecting the hypothalamus to the pituitary, then prolactin levels rise because the inhibitory effect of the hypothalamus is lost. Such damage can occur as a result of head trauma or surgery or from an enlarging tumor of the pitutiary gland or structures close to the pituitary gland.
Drugs that mimick the effect of dopamine reduce the production of prolactin and are therefore useful in a person with a prolactin-secreting pituitary tumor. The main drugs available for this purpose are those I listed at the outset: bromocriptine and cabergoline. The effect is lost within a matter of hours to days when the drugs are stopped, so they are generally used long-term.