A randomized cross-over study comparing cabergoline and quinagolide in thetreatment of hyperprolactinemic patients

Quinagolide (QUI) and cabergoline (CAB) are dopamine agonists recently intr oduced for the treatment of hyperprolactinemia. In the present study, these drugs have been compared in terms of effectiveness and tolerability. Twent y patients (18 females and 2 males) with hyperprolactinemia (8 with micropr olactinomas, 6 with idiopathic hyperprolactinemia and 6 with empty sella tu rcica syndrome) were treated with oral QUI (75 mu g once daily) and CAB (0, 5 mg twice weekly), in a randomized cross-over trial with placebo between b oth drugs. Each drug was administered for 12 weeks, separated by other 12 w eeks with placebo. PRL levels decreased with both drugs at 2 or 4 weeks of starting the treatment, without differences between both drugs at weeks 4, 8 and 12. At week 12, normal PRL levels (<20 ng/ml) were attained in 90% pa tients with CAB and only in 75% patients with QUI (p<0.05). After discontin uation of treatment, significant increase in serum PRL was higher after QUI withdrawal than after CAB. Clinical efficacy of both treatments was simila r in terms of improvement amenorrhea, oligomenorrhea, galactorrhea, and imp otence. All patients completed both cycles of treatment, and the most frequ ent side-effects were nausea, headache and dizziness, without significant d ifferences between CAB (30%) and QUI (55%). Our study indicates that, at th e doses employed here, CAB showed a high percentage of patients with normal PRL at the end of treatment and long-lasting efficacy in the levels of PRL . Clinical response and side-effects were similar in both drugs. (C) 2000, Editrice Kurtis.