In some people, high blood levels of prolactin can be traced to causes other than a pituitary tumor.
Causes of prolactinoma
Kidney disease (renal failure)
Breast stimulation also can cause a modest increase in the amount of prolactin in the blood
Other pituitary and non-pituitary tumors in arising in or near the pituitary may block the flow of dopamine from the brain to the prolactin-secreting cells leading to hyperprolactinemia.
Prescription drugs can also cause prolactinoma
Prolactin secretion in the pituitary is normally suppressed by the brain chemical, dopamine. Drugs that block the effects of dopamine at the pituitary or reduce dopamine stores in the brain may cause the pituitary to secrete excess prolactin. These drugs include medicines for psychiatric disorders.
Medicines for psychiatric disorders such as haloperidol (Haldol) and serotonin reuptake inhibitors (SSRIs, such as Prozac)
metoclopramide (Reglan), used to treat gastroesophageal reflux and nausea.
Some calcium channel blockers, including verapamil