Abstract :
Recent clinical trials show that low-dose estrogen reduces the number of moderate-to-severe vasomotor episodes by 65%. This reduction is about midway between the 35% to 40% reduction observed with placebo and the 75% to 80% reduction observed with standard dosage. Compared with standard dosages whose effects are substantial by 4 weeks, relief with lower dosages is not maximal until 8 to 12 weeks. Women using lower dosages of estrogen experience 50% lower rates of irregular bleeding or breast tenderness compared with individuals taking standard dosages. Despite several lower dosage hormone therapy (HT) formulations being approved by the US Food and Drug Administration (FDA) and brought to market, their uptake by healthcare providers has been slow. Most women who have continued HT after reports of the Women’s Health Initiative (WHI) were published take estrogen in a standard dosage; only a minority of these individuals report receiving guidance about switching to a lower dosage. The purpose of this review is to summarize the clinical trial data showing, on one hand, effects of various dosages of estrogen on vasomotor symptoms and, on the other hand, the effects of these same dosages on troublesome adverse events, particularly vaginal bleeding or breast tenderness. Based on the balance of symptom benefit versus symptom nuisance, it is time to reconsider what should be the current estrogen dosage recommendation. Furthermore, healthcare providers need to learn how and when to prescribe lower dosages of HT to optimize patient acceptance and continuation.
