Objective: This post hoc analysis estimates time to transient and stable reductions in hot flush frequency in postmenopausal women using conjugated estrogens/bazedoxifene.
Methods: In the 12-week Selective estrogens, Menopause, And Response to Therapy (SMART)-2 trial of conjugated estrogens/bazedoxifene 0.45 mg/20 mg and 0.625 mg/20 mg, women with at least seven moderate/severe hot flushes per day or 50 per week at screening recorded frequency of moderate/severe hot flushes in diaries. Nonparametric models and SAS Proc Lifetest were used to estimate median times to various degrees of transient reductions (first day with improvement) and stable reductions (first day with improvement maintained through study's end) in hot flush frequency.
Results: Treatment produced transient hot flush reductions of 40% to 100% and stable reductions of 30% to 100% significantly faster than placebo. Median time to a transient 50% reduction was 8 days for conjugated estrogens/bazedoxifene 0.45 mg/20 mg, 9.5 for 0.625 mg/20 mg, and 10 for placebo; median time to a stable 50% reduction was 9, 10, and 38 days. Median time to a transient 90% reduction was 32 and 22.5 days for 0.45 mg/20 mg and 0.625 mg/20 mg, and median time to a stable 90% reduction was 83 and 29 days, respectively; median times to transient/stable 90% reductions were not reached during the 12-week study in the placebo group.
Conclusions: Although not all women using conjugated estrogens/bazedoxifene achieve permanent elimination of hot flushes, the frequency is likely to be substantially reduced during the first week to month. Women can expect approximately 50% reduction in hot flush frequency after about 8 to 10 days, and sustained improvement with continued treatment.