A topical estradiol gel formulation has been approved for treating moderate to severe vasomotor symptoms associated with menopause. The gel is available under the trade name Elestrin from BioSante Pharmaceuticals Inc.
A transdermal product that is invisible is a good option “for women not wanting an oral product or where there's reason not to prescribe an oral product, and [for women who] are not keen on a visible patch,” said Dr. Wulf Utian, the executive director of the North American Menopause Society, and a consultant in women's health at the Cleveland Clinic. There are other estrogen gel products marketed; the 0.87-g dose of Elestrin is the lowest available dose of a gel product.
The Elestrin label contains contraindications, precautions, and warnings that are standard for the entire class of estrogen products.
In a 12-week study comparing different Elestrin doses with placebo in 484 symptomatic menopausal women with at least 60 moderate to severe hot flushes per week, the frequency and severity of hot flushes were significantly reduced by week 4 in the women on the 1.7-g daily dose and by week 5 in the women on 0.87-g daily dose, compared with those on placebo. The reductions in severity and frequency remained significant compared with placebo at 12 weeks of treatment, at which time the women on the higher dose had a mean of about three hot flushes per day, those on the lower dose had a mean of about five per day, and those on placebo had a mean of about eight per day.
Elestrin is applied in a thin layer to the upper arm once a day, starting at the lower approved dose, 0.87 g/day (0.52 mg of estradiol). If needed, dosage can be increased to 1.7 g/day (1.04 mg estradiol). (One pump actuation of the Elestrin applicator delivers 0.87 g; two actuations deliver 1.7 g.)
As in other dose-comparison studies of estrogen products, the Elestrin study showed that the lower dose takes a little more time to be effective but then is almost as effective as the higher dose, said Dr. Utian, an investigator in the study. “You get virtually the same level of efficacy, but it just takes a week or so longer to kick in, so the recommendation in practice is to advise the women that a low dose may take a little longer to reach efficacy, but don't start swapping doses too soon for higher doses because it's worth waiting.”
The general belief is that the lower the estrogen dose, the less likely it is that there will be side effects, such as thromboembolism; this is “probably true,” but there are still no long-term data confirming this, he said.
Dr. Utian said he has no financial ties to BioSante Pharmaceuticals.