Hyperprolactinemic amenorrhea:treatment with cabergoline versus bromocriptine. Results of a national multicenter randomized double-blind study

OBJECTIVES:

Cabergoline is a new, long-acting D2 agonist, highly effective in suppressing prolactin and restoring gonadal function in hyperprolactinaemic amenorrhoea. This study compares its efficacity and safety with that of the reference compound, bromocriptine.

METHODS:

A prospective study involved 21 French Centres and 120 women, with hyperprolactinaemic amenorrhoea, randomized to either cabergoline (CAB 0.5-1 mg twice weekly) or bromocriptine (BRC 2.5-5 mg twice daily). Treatment is given under double-blind conditions for the first 8 weeks, and subsequently in open conditions in further 16 weeks with dose adjustments according to response. Patients were assessed for biochemical and clinical efficacy and drug safety (adverse symptoms and biology).

RESULTS:

Normoprolactinaemia was achieved in 56/60 (93.3%) taking CAB and 27/58 (48.2%) taking BRC (p < 0.0001). Ovulatory cycles or pregnancy were recorded in 71.6% and 48.2% of patients (p = 0.001). Prolactin suppression to below 50% of the baseline value was observed in 1.6% and 15.5% (p = 0.007). Adverse symptoms were recorded in 31/60 (51.6%) and 40/58 (69.2%) patients respectively in the double-blind period, and 53.3% versus 65.5% for the full course of the study. There were significantly fewer gastro-intestinal symptoms in the CAB group, 36.6% versus 84.5% (p < 0.0001).

CONCLUSION:

Cabergoline is a new prolactin-lowering drug, more effective and better tolerated with fewer gastrointestinal symptoms than the reference compound, bromocriptine.