Aside from a prolactinoma, what else can cause prolactin levels to rise?
In some people, high blood levels of prolactin can be traced to causes other than a prolactinoma. Other causes include: • Prescription drugs: Prolactin secretion in the pituitary is normally suppressed by the brain chemical, dopamine. Drugs that block the effects of dopamine at the pituitary or deplete dopamine stores in the brain may cause the pituitary to secrete prolactin. These drugs include the major tranquilizers trifluoperazine (Stelazine) and haloperidol (Haldol); metoclopramide (Reglan) used to treat gastroesophageal reflux and the nausea caused by certain cancer drugs; and less often, alpha methyldopa and reserpine (Harmonyl) used to control hypertension. • Other pituitary tumors: Other tumors may block the flow of dopamine from the brain, which normally inhibits its prolactin-secreting cells. Such so-called “mixed” tumors arise in or near the pituitary, and include those that release excessive growth hormone (acromegaly) or stimulate cortisol production (Cushing’s syndrome).
