A COMPARISON OF CABERGOLINE AND BROMOCRIPTINE IN THE TREATMENT OF HYPERPROLACTINEMIC AMENORRHEA

Background. Cabergoline is a long-acting dopamine-agonist drug that su ppresses prolactin secretion and restores gonadal function in women wi th hyperprolactinemic amenorrhea. We designed a study to compare its s afety and efficacy with those of bromocriptine, which has been the sta ndard therapy. Methods. A total of 459 women with hyperprolactinemic a menorrhea were treated with either cabergoline (0.5 to 1.0 mg twice we ekly) 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 f or 16 weeks, during which adjustments in the dose were made according to the response. Of the 459 women, 279 had microprolactinomas, 3 had m acroprolactinomas, 1 had a craniopharyngioma, 167 had idiopathic hyper prolactinemia, and the remainder had an empty sella. Clinical and bioc hemical status was assessed at 2-week intervals for 8 weeks and monthl y thereafter for a total of 6 months, with an additional assessment at 14 weeks. Results. Stable normoprolactinemia was achieved in 186 of t he 223 women treated with cabergoline (83 percent) and 138 of the 236 women treated with bromocriptine (59 percent, P<0.001). Seventy-two pe rcent of the women treated with cabergoline and 52 percent of those tr eated with bromocriptine had ovulatory cycles or became pregnant durin g treatment (P<0.001). Amenorrhea persisted in 7 percent of the caberg oline-treated women and 16 percent of the bromocriptine-treated women. Adverse effects were recorded in 68 percent of the women taking caber goline and 78 percent of those taking bromocriptine (P = 0.03); 3 perc ent discontinued taking cabergoline, and 12 percent stopped taking bro mocriptine (P<0.001) because of drug intolerance. Gastrointestinal sym ptoms were significantly less frequent, less severe, and shorter-lived in the women treated with cabergoline. Conclusions. Cabergoline is mo re effective and better tolerated than bromocriptine in women with hyp erprolactinemic amenorrhea.