Objective To investigate the efficacy of toremifene in the treatment of premenstrual mastalgia.
Design Double-blind, placebo-controlled crossover study.
Setting Three Finnish general practices from the districts of Satakunta Central Hospital and Tampere University Hospital.
Population A total of 62 women aged 25–45 years with premenstrual mastalgia during at least three previous menstrual cycles.
Methods Women were randomised to receive toremifene 20 mg daily or placebo from day 15 of the menstrual cycle until menstruation for three consecutive cycles. After a wash-out cycle, the women were crossed over to receive placebo or toremifene for three additional cycles.
Main outcome measures Cyclic breast pain relief assessed by visual analogue scale (VAS) score. Quality-of-life scores assessed by a modified 36-item Finnish Depression Scale, with a score ranging from 0 to 108. Acceptability of treatment.
Results About 32 women were randomised to receive toremifene first and 30 to receive placebo first. Twenty-nine and 27 participants in the groups treated with toremifene first or placebo first completed the treatment, respectively. There were significant reductions in VAS scores in both groups after three treatment cycles. This was significantly greater in the toremifene-treated group (VAS: 1.8 in the toremifene group and 3.7 in the placebo group, P= 0.004). Treatment effect between treatment cycles was significant (P= 0.001). Quality of life was similar during the toremifene and placebo cycles.
Conclusion This study demonstrates that the antiestrogenic compound, toremifene, is able to relieve premenstrual breast pain without major adverse effects. There was a 64% reduction in median pain scores in the toremifene-treated cycles compared with a 26% reduction in placebo-treated cycles.