Clinical Question: Are commonly used estrogens equally safe and effective in the treatment of menopausal hot flushes?

Setting: Population-based

Study Design: Systematic review

Synopsis: Low-dose estrogen in various forms is used commonly to treat menopausal symptoms. To compare the efficacy and safety of different estrogen types and delivery systems, the author systematically reviewed multiple databases, including MEDLINE, EMBASE, the Cochrane Controlled Trials Registry, reference lists of published articles, expert opinions, and pharmaceutical company publications. The author included English-language articles of double-blind randomized controlled trials of oral conjugated estrogen, and oral and transdermal 17β-estradiol. A total of 32 trials met inclusion criteria, including four head-to-head comparisons.

All estrogen types significantly reduced hot flushes compared with placebo, but no significant differences in efficacy were evident between the types or delivery methods (i.e., oral versus transdermal). Adverse effects, most commonly breast tenderness and atypical vaginal bleeding, occurred at a similar rate regardless of the type of estrogen or mode of delivery. No differences were reported about the influence of progesterone on efficacy and adverse effects.

Bottom Line: Commonly used estrogens, including oral conjugated equine estrogen, and oral or transdermal 17β-estradiol, are equally safe and effective in the treatment of menopausal hot flushes. This analysis did not include phytoestrogens because no direct comparisons have been made with standard estrogen replacement. (Level of Evidence: 1a)