Initial 17 beta-estradiol dose for treating vasomotor symptoms

Objective: To compare the efficacy of different doses of 17 beta-estradiol (E2) for relief of vasomotor symptoms in menopausal women. Methods: This was a randomized, double-masked, placebo-controlled, 12-week study in which 333 menopausal women with moderate or severe hat flushes wer e assigned to treatment with 0.25 mg, 0.5 mg, 1 mg, or 2 mg oral micronized 17 beta-E2, or placebo. The number and severity of hot flushes were record ed daily. Results: There was a significant linear correlation between increased dosag e of 17 beta-E2 and decreased moderate to severe hot flushes per week (P < .001). Rapid reduction in moderate to severe hot flushes was only achieved with 1 and 2 mg, showing a significant difference from placebo at week 4 (P < .05). At week 4, half the women on placebo had reduced moderate to sever e hot flushes of at least 52%; the corresponding figures were 56%, 69%, 86% , and 91% for 0.25, 0.5, 1, and 2 mg, respectively. At week 12, all doses e xcept 0.25 mg were significantly better than placebo for reducing moderate to severe hot flushes (P < .001). Although there were no significant differ ences, twice as many women in the 2-mg group discontinued treatment due to adverse events, compared with the placebo group. Conclusion: Oral micronized 17 beta-E2 showed a dose-response effect for re ducing moderate and severe hot flushes in menopausal women. 17 beta-E21 mg appeared to be the most useful initial dose. (C) 2000 by The American Colle ge of Obstetricians and Gynecologists.