Levonorgestrel

The Food and Drug Administration has approved the Climara Pro transdermal patch--the first once-a-week, combined hormone therapy for moderate to severe vasomotor symptoms associated with menopause.

"Patients appreciate the convenience of a once-a-week patch--it's a great advantage," said Dr. JoAnn M Pinkerton, medical director of the Midlife Health Center, University of Virginia, Charlottesville.

No other menopausal therapy on the U.S. market contains levonorgestrel, a type of progestin. Progestin therapy is indicated for women who have an intact uterus. Levonorgestrel has been used safely in women's health care products for more than 20 years, according to Kimberly Schillace, a spokeswoman for Berlex, the patch's manufacturer.

The new patch will be available by the middle of the month, she said.

Since the publication in 2002 of findings from the Women's Health Initiative (WHI) on oral hormone therapy (HT) with conjugated equine estrogens (0.625 mg/day) and medroxyprogesterone acetate (2.5 mg/day), there has been concern that high levels of estrogen can be harmful.

Climara Pro delivers a lower dose of estradiol (0.045 mg/day of estradiol and 0.015 mg/day of levonorgestrel) than CombiPatch, the first estrogen and progestin patch on the U.S. market.

"The overall trend is to use the lowest effective dose for the shortest period while symptoms persist," Dr. Pinkerton said.

Two randomized, controlled clinical trials showed that Climara Pro significantly reduced the frequency and severity of hot flashes as early as 1 week into therapy, and that 90% of women experienced an 80% reduction in hot flashes by week 12, according to Berlex Inc., a U.S. affiliate of Schering AG Germany, Berlin.

The transdermal patch is "extremely well tolerated," and few skin problems were reported by patients during clinical trials, said Dr. James A. Simon, who has conducted research on the patch and is on the speakers' bureau for Berlex.

Low rates of nausea and gastrointestinal complaints were reported with the patch.

Transdermal delivery also avoids first-pass effects through the liver during absorption, which helps avoid drug-drug interactions. Unlike oral therapy, transdermal delivery doesn't appear to increase triglycerides or sex hormone-binding globulin.

"Another potential advantage [of Climara Pro] was that the patch had no impact on weight gain, which many patients are concerned about," said Dr. Simon, who is president of the North American Menopause Society.

Although there are no data on Climara Pro or any other hormone patch that are similar in scope to the data obtained in the WHI study, the Million Women Study in the United Kingdom showed slight increases in breast cancer with all estrogen and progestin combinations, including oral and patch forms, Dr. Pinkerton said.

"Without more data, one must assume risks similar to those seen in the WHI, particularly with regard to slight increases in breast cancer risks," she added.

It is unclear whether the risk of heart events and strokes will increase with the patch, but transdermal dosing may impart less risk of blood clots, though there are no data currently available to support this contention with this patch, she said.

COPYRIGHT 2004 International Medical News Group
COPYRIGHT 2004 Gale Group