Controlled trial of the prolactin inhibitor bromocriptine (Parlodel) in the treatment of severe cyclical mastalgia.

Fifty pre-menopausal women with severe and persistent cyclical mastalgia entered this randomised, double-blind, parallel group study comparing bromocriptine and placebo. Patients were treated for three months followed by a further three months on the same medication if treatment was satisfactory. Symptoms were assessed before treatment and after one, two and three months of treatment. For patients whose mastalgia was not controlled after three months, the treatment code was broken and either the dose of bromocriptine increased or the patient given active medication instead of placebo. Bromocriptine, compared with placebo, caused a significant (p less than 0.01) and sustained improvement in breast pain, tenderness and nodularity together with a reduction in serum prolactin levels (p less than 0.01). Adverse events were experienced by 9/23 (39 per cent) of patients taking bromocriptine and 2/22 (nine per cent) taking placebo. The majority of side effects reported were mild or moderate. This study shows that bromocriptine, at a dose of 5 mg/day for three months, effectively controls the symptoms of cyclical mastalgia with minimal side effects.