Tumor prolactin-secreting

Review the available diagnostic data to determine pituitary tumor size and location. Determine if the patient has a coexisting prolactin-secreting tumor. Determine if the tumor extends toward the optic chiasm or if it is continuous on the optic tracts. 

Headache and compromised or loss of vision caused by the prolactin-secreting tumor and its close proximity to the optic structures. 

Increased body weight may be associated with prolactin-secreting pituitary tumor. 

Bromocriptine (Parl el) [Antiparkinsonian Agent/Dopamine Receptor Agonist] Uses Parkin on Dz, hyperprolactinemia, acromegaly, pituitary tumors Action Direct-acting on the striatal dopamine receptors X prolactin secretion Dose Initial, 1.25 mg PO bid titrate to effect, w/ food Caution [B, ] Contra Severe ischemic heart Dz or PVD Disp Tabs, caps SE X BP, Raynaud phenomenon (vasospastic disorder resulting in discoloration of the fmgers/toes), dizziness, N, hallucinations Interactions T Effects W/ erythromycin, fluvoxamine, nefazodone, sympathomimetics, antihypertensives X effects W/ phenothiazines, antipsychotics EMS Monitor BP may cause intolerance to EtOH OD May cause NA, severe hypotension give IV fluids symptomatic and supportive... 

Dopamine inhibits prolactin synthesis. Drugs that inhibit dopamine synthesis or activity (e.g. antihypertensives, antidepressants, estrogen, phenothiazines, opiates), are the most common cause of hyperprolactinemia. Prolactin-secreting pituitary tumors sometimes are treated with bromocriptine, a dopamine agonist. 

Bulatov AA, Martynov AV, Grigor ian AL, Komolov IS. Molecular forms of human growth hormone and prolactin, secreted by cultured pituitary tumor cells. Biokhimiia 1995 60 1637-46. 

The patient may complain of symptoms related to local effects of the prolactin-secreting tumor, such as headache and visual disturbances, that result from tumor compression of the optic chiasm. 

Hyperprolactinemia is a common disorder that can have a significant impact on fertility. Hyperprolactinemia is most commonly caused by the presence of prolactin-secreting pituitary tumors and various medications that antagonize dopamine or increase the secretion of prolactin. Available treatment options for this disorder include medical therapy with dopamine agonists, radiation therapy, and transsphenoidal surgery. In most cases, medical therapy with dopamine agonists... 

The clinical term for excessive release of prolactin is hyperprolactinemia. It is actually a relatively common disorder in humans. There are many causes that initiate the condition including prolactin-secreting tumors and therapy with certain drugs. 

Restoration of pituitary prolactin synthesis and release by the administration of morphine to rats bearing a transplanted prolactin-secreting tumor... 

Hyperprolactinemia and parkinsonism Bromocriptine and pergolide are used to reduce prolactin secretion (dopamine is the physiologic prolactin release inhibitor). Bromocriptine also appears to reduce the size of pituitaiy tumors of the prolactin-secreting cells. This drug is also useful in the treatment of Parkinson s disease (Chapter 27). 

F. Prolactin-Inhibiting Hormone (PIH, Dopamine) Dopamine is the physiologic inhibitor of prolactin release. Because of its peripheral effects and the need for parenteral administration, dopamine is not useful in the control of hyperprolactinemia, but bromocriptine and other orally active ergot derivatives (eg, cabergoline. pergolide) are effective in reducing prolactin secretion from the normal gland as well as from pituitary tumors. 

As many as 25% of infertile women have hyperprolactinemia. In women, hyperprolactinemia causes galactorrhea, oligomenorrhea, or amenorrhea as well as infenility (the amenorrhea-galactorrhea syndrome). While prolactin-secreting tumors are the most common cause of hyperprolactinemia, the condition can also be precipitated by treatment with dmgs that interfere with the control of prolactin release. 

F. Use in pregnancy. FDA category B (see p 405). This dmg has been used therapeutically during the last trimester of pregnancy for treatment of a pituitary tumor. It has been shown to inhibit fetal prolactin secretion, and it may precipitate premature labor and inhibit lactation in the mother. 

Piroli, G., Grillo, C., Ferrini, M., Diaz, Torga, G., Libertun, C. and De-Nicola, A.E (1993) Restoration by bromocriptine of glucocorticoid receptors and glucocorticoid negative feedback on prolactin secretion in estrogen-induced pituitary tumors. Neuroendocrinology, 58, 273—279. 

Dopamine agonists may be appropriate for patients with mildly elevated insulin-like growth factor I levels who have growth hormone and prolactin co-secreting tumors. 

A dopamine agonist alone or in combination with pituitary surgery, radiation therapy, or octreotide administration can be used to treat acromegaly. The doses required are higher than those used to treat hyperprolactinemia. For example, patients with acromegaly require 20-30 mg/d of bromocriptine and seldom respond adequately to bromocriptine alone unless the pituitary tumor secretes prolactin as well as GH. 

Increased serum levels of the anterior pituitary hormone prolactin are associated with secreting tumors of the gland and also with the use of centrally acting dopamine antagonists, especially the... 

Administration of estrogens is well known to cause an increase in plasma prolactin (PRL) levels in man (43, 44) as well as in the rat (45-48). This stimulatory effect of estrogens is also observed in vitro in anterior pituitary gland explants (49), tumoral adenohypophysial cells (50) and normal rat anterior pituitary cells in primary culture (39, 40, 42, 51). Seventeen-g-estradiol (E2) does not only stimulate basal and TRH-induced PRL secretion in rat anterior pituitary cells in culture but it can also reverse almost completely the inhibitory effect of dopamine (DA) agonists on PRL release (40). 

Hypoprolactinemia is a hormonal imbalance with elevated levels of prolactin. Prolactin is normally elevated in nursing mothers, but abnormal amounts can cause impotence in men and amenorrhea and secretion of breast milk in women. A physician must first rule out the presence of a prolactinoma (pituitary tumor), but if there is no such tumor, saw palmetto along with white sage (Salvia apiana) and chaste tree (Vitex agnus-castus) may be of benefit. 

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