Abstract/Text: After infancy, galactorrhea usually is medication-induced. The most common pathologic cause of galactorrhea is a pituitary tumor. Other causes include hypothalamic and pituitary stalk lesions, neurogenic stimulation, thyroid disorders, and chronic renal failure. Patients with the latter conditions may have irregular menses, infertility, and osteopenia or osteoporosis if they have associated hyperprolactinemia. Tests for pregnancy, serum prolactin level and serum thyroid-stimulating hormone level, and magnetic resonance imaging are important diagnostic tools that should be employed when clinically indicated. The underlying cause of galactorrhea should be treated when possible. The decision to treat patients with galactorrhea is based on the serum prolactin level, the severity of galactorrhea, and the patient's fertility desires. Dopamine agonists are the treatment of choice in most patients with hyperprolactinemic disorders. Bromocriptine is the preferred agent for treatment of hyperprolactin-induced anovulatory infertility. Although cabergoline is more effective and better tolerated than bromocriptine, it is more expensive, and treatment must be discontinued one month before conception is attempted. Surgical resection rarely is required for prolactinomas.

Abstract/Text: BACKGROUND: Cabergoline is a long-acting dopamine-agonist drug that suppresses prolactin secretion and restores gonadal function in women with hyperprolactinemic amenorrhea. We designed a study to compare its safety and efficacy with those of bromocriptine, which has been the standard therapy.
METHODS: A total of 459 women with hyperprolactinemic amenorrhea were treated with either cabergoline (0.5 to 1.0 mg twice weekly) or bromocriptine (2.5 to 5.0 mg twice daily), administered in a double-blind fashion for 8 weeks and subsequently in an open fashion for 16 weeks, during which adjustments in the dose were made according to the response. Of the 459 women, 279 had microprolactinomas, 3 had macroprolactinomas, 1 had a craniopharyngioma, 167 had idiopathic hyperprolactinemia, and the remainder had an empty sella. Clinical and biochemical status was assessed at 2-week intervals for 8 weeks and monthly thereafter for a total of 6 months, with an additional assessment at 14 weeks.
RESULTS: Stable normoprolactinemia was achieved in 186 of the 223 women treated with cabergoline (83 percent) and 138 of the 236 women treated with bromocriptine (59 percent, P < 0.001). Seventy-two percent of the women treated with cabergoline and 52 percent of those treated with bromocriptine had ovulatory cycles or became pregnant during treatment (P < 0.001). Amenorrhea persisted in 7 percent of the cabergoline-treated women and 16 percent of the bromocriptine-treated women. Adverse effects were recorded in 68 percent of the women taking cabergoline and 78 percent of those taking bromocriptine (P = 0.03); 3 percent discontinued taking cabergoline, and 12 percent stopped taking bromocriptine (P < 0.001) because of drug intolerance. Gastrointestinal symptoms were significantly less frequent, less severe, and shorter-lived in the women treated with cabergoline.
CONCLUSIONS: Cabergoline is more effective and better tolerated than bromocriptine in women with hyperprolactinemic amenorrhea.