Review Question - QID 102974

This patient has galactorrhea and amenorrhea, with a negative pregnancy test; which is highly suggestive of hyperprolactinemia. Appropriate therapy is with dopamine agonists such as cabergoline or bromocriptine.

Hyperprolactinemia, or elevated serum prolactin, is a common condition often due to pregnancy, medication side-effects, or prolactin secreting pituitary tumors (prolactinoma). If unrecognized, hyperprolactinemia can result in hypogonadism, infertility, and eventually galactorrhea. Aside from reproductive symptoms, patients with prolactinomas may present with headaches and if it's large enough, bitemporal hemianopsia due to mass effect on the optic chiasm. Diagnosis is through serum prolactin levels being >250 mcg/L. Medical therapy is directed at suppressing prolactin secretion via dopamine agonists such as cabergoline or bromocriptine.

Huang et al. discuss the approach to galactorrhea in the outpatient setting. They comment that hyperprolactinemia is usually secondary to prolactinomas or iatrogenic (dopamine antagonists). More rare causes include hypothyroidism, renal insufficiency, pregnancy, and nipple stimulation.

Melmed et al. discuss the Endocrine Society's clinical guidelines for hyperprolactinemia. They conclude that dopamine agonists are 80-90% efficacious in the treatment of prolactinomas, with effective reduction in serum prolactin levels, as well as reduction in tumor size. Transsphenoidal surgery is reserved for patients with prolactinomas refractory to medical therapy.

Incorrect Answers:
Answer 1: Tamoxifen is a selective estrogen receptor modulator, used in to treat estrogen receptor positive breast cancer. This patient's presentation is not suggestive of breast cancer.
Answer 2: Leuprolide is a GnRH agonist which is can be used to suppress or stimulate the Hypothalamic-pituitary-gonadal axis, for example in the setting of precocious puberty.
Answer 3: Haloperidol is a typical antipsychotic which functions in part through CNS dopamine antagonism. Dopamine antagonism in the tuberoinfundibular tract by antipsychotics can result in iatrogenic hyperprolactinemia.
Answer 5: Carbidopa-Levodopa is dopamine replacement therapy for patients with Parkinson's Disease, it has no role to place in the treatment of hyperprolactinemia.