Medical therapy with dopamine agonists (DA) is the preferred initial treatment for the vast majority of patients harboring prolactinomas. Eur J Endocrinol. Neurosurg Focus. Long-term and low-dose treatment with Cabergoline induces macroprolactinoma shrinkage. They may also be ordered at regular intervals to monitor for prolactinoma recurrence.Prolactin levels may be ordered, along with other hormone levels such as growth hormone, when a health practitioner suspects that a person has a pituitary disorder such as hypopituitarism.When a person has a condition or is taking medications that may affect dopamine production, prolactin concentrations may sometimes be monitored.Prolactin is secreted in a pulsatile manner, with a distinct circadian pattern Men and non-pregnant women will normally have only small amounts of prolactin in their blood. Factors that stimulate prolactin secretion to upregulate prolactin gene transcription while factors that inhibit prolactin secretion downregulate prolactin gene transcription. 1981;98:171–7.Colao A, Sarno AD, Cappabianca P, Briganti F, Pivonello R, Somma CD, et al. Macroprolactin is detected by differing degrees depending on the immunoassay used to measure prolactin. Macroadenomas (>10 mm in diameter) are typically associated with serum prolactin concentrations above 250 ng/mL, and a concentration above 500 ng/mL is diagnostic of a macroprolactinoma. The most common symptom complex of anterior pituitary dysfunction in men and women is secondary hypogonadism caused by deficiencies of luteinizing hormone (LH) and follicle-stimulating hormone (FSH).Currently, no medication exists to treat prolactin deficiency; however, experimental recombinant human prolactin has been formulated and has been shown to be effective in correcting lactational performance in rats treated with bromocriptine Inadequate lactation may respond to antidopaminergic agents that block the dopamine-induced hypothalamic inhibitory control of prolactin. alpha-methyldopa and reserpine) are capable of depleting the central dopamine stores.Section of the pituitary stalk results in impaired transport of dopamine from the hypothalamus to the lactotrophs. 2005;147:151–7. J Clin Endocrinol Metab. This sequence of events results in hyperprolactinemia.Hypothyroidism may be associated with hyperprolactinemia. 2002;87:3180–6.Nomikos P, Buchfelder M, Fahlbusch R. Current management of prolactinomas. When measuring PRL levels using a two-site immunometric method, such as immunoradiometric assay (IRMA) or chemiluminescent immunoassay (ICMA), a very high PRL concentration might saturate the binding sites, causing falsely low PRL results. J Endocrinol Invest. 2003;58:662–70.Cho EH, Lee SA, Chung JY, Koh EH, Cho YH, Kim JH, et al. This leads to inhibition of the ovulatory cycle in females which explains the lactational amenorrhea. Human prolactin circulates as monomeric prolactin and as larger forms which are indistinguishable by routine assays. Outcome of cabergoline treatment in men with prolactinoma: Effects of a 24-month treatment on prolactin levels, tumor mass, recovery of pituitary function, and semen analysis. Organs that might be harmed include the optic chiasm, the cranial nerves located in the cavernous sinuses (namely the optic, trochlear, abducens and two branches of the trigeminal nerves) and other adjacent structures, such as the temporal lobe, the nasal cavity and sinuses, the internal ear and the thalamus. 2,3 Cabergoline is a newer agent, with greater selectivity for the D 2 receptor than bromocriptine. Prolactin is the principal hormone that controls the initiation and maintenance of lactation. Diagnostically, PRL gradually increases throughout pregnancy and cannot be used for the estimation of tumor size dynamics. Metoclopramide has been shown in prospective, placebo-controlled studies to significantly increase milk yield in patients with inadequate lactation In one study, normal sperm characteristics were restored when prolactin levels were raised to normal values in hypoprolactinemic men What other tests may be done to evaluate high prolactin levels?If I have high prolactin, why is my doctor testing my thyroid?Can dopamine agonist drug be withdrawn without recurrence of hyperprolactinemia?1, 2, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19. Certain drugs act as dopamine-receptor-blocking agents, including phenothiazines (e.g. Sometimes, despite medication and/or surgery, the prolactinoma recurs.A number of otherwise healthy people have elevated prolactin levels because some of the prolactin in their blood is in a different form called macroprolactin. 2010;362:1219–26.Ciccarelli A, Guerra E, Rosa M, Milone F, Zarrilli S, Lombardi G, et al. Macroprolactinemia is a common finding, some reporting it as frequently as 8 to 42% of all cases; other centers find that it is extremely rare. Emerging clinical data indicate that dopaminergic agonists used to treat restless legs syndrome may be associated with dopamine dysregulation syndrome, particularly pathological gambling.