A multi-institutional research group has found that use of an experimental testosterone skin patch can relieve impaired sexual functioning in surgically menopausal women - that is, women who have had their ovaries removed before natural menopause. The report in the Sept. 7 New England Journal of Medicine comes from a team led by researchers from the Massachusetts General Hospital (MGH) and Watson Laboratories, Inc.-Utah, a division of Watson Pharmaceuticals (NYSE:WPI), the developers of the patch.
The study was supported by Procter and Gamble Pharmaceuticals (NYSE:PG), which has licensed the marketing rights for the testosterone patch and is currently developing the product in collaboration with Watson Laboratories.
"We know that women who have gone through menopause after surgical removal of their ovaries have decreased testosterone levels," says Jan Shifren, MD, of the MGH Vincent Memorial Obstetrics and Gynecology Service, the paper's lead author. "This study indicates that women who have experienced a loss of sexual functioning after such surgery may benefit from returning their testosterone levels to normal through use of a testosterone skin patch."
Women produce testosterone in their ovaries and adrenal glands and may require sufficient levels of the hormone for proper sexual functioning. About half of a woman's testosterone comes from the ovaries, and as a result women whose ovaries are removed before menopause lose about half their natural testosterone, along with 80 percent of their natural estrogens. Although testosterone is generally considered "the male hormone," it is also an important hormone for women.
While estrogen replacement therapy can relieve symptoms such as hot flashes, vaginal atrophy and osteoporosis in women who have had their ovaries removed, many such women who take estrogen still report a loss of sexual desire, activity and pleasure, as well as reduced overall sense of well being.
Norm Mazer, MD, PhD, senior medical research fellow at Watson Labs and the study's designer, says, "This study was built on the work of earlier researchers who first recognized the potential of testosterone to improve sexual functioning in women after surgical menopause. But these earlier studies treated women with testosterone injections or implants, which resulted in higher than normal serum testosterone levels. The testosterone patches developed by Watson Laboratories were specifically designed to restore testosterone levels to the normal range of healthy young women."
The research team enrolled 75 women, ages 31 to 56, who had undergone hysterectomy and oophorectomy (surgical removal of the ovaries) from one to 10 years before the study began. Prior to treatment all participants had testosterone levels that were below average in comparison to healthy young women, and despite daily oral estrogen replacement therapy, all reported having less active or less satisfying sex lives as compared with before their surgery.
During the 36-week study, the women went through three consecutive 12-week treatment periods during which they received, in random order, three combinations of skin patches. The patches delivered daily doses of either 300 micrograms of testosterone, 150 micrograms of testosterone, or a placebo. Neither the participants nor the investigators working with them knew which patch combinations the women were receiving at any time. The women completed an evaluation of sexual functioning - including desire, arousal, activity and pleasure - as well as an evaluation of overall psychological well being, at the beginning of the study and at the end of each treatment period. Testosterone levels were measured at four-week intervals, and the participants continued to receive oral estrogen replacement therapy throughout the study.
Data sufficient for analysis was gathered for 65 study participants. The women reported increased sexual activity and pleasure in all three treatment periods, including placebo, but significantly greater improvement was seen at the 300 microgram dose level compared to placebo. The women also reported improved overall psychological well being with treatment. Adverse side effects of the type often associated with excess testosterone levels were not reported at significant levels. Most importantly the levels of HDL-cholesterol, the so-called "good cholesterol," were not lowered by transdermal testosterone treatment.
Testosterone levels remained low during placebo periods but rose to mid-normal and high-normal levels when women received the 150- and 300-microgram doses, respectively. The testosterone treatments had no effect on the participants' estrogen levels.
The researchers noted that even women receiving placebo doses reported improved sexual functioning compared with their experiences before starting the study. They note that a number of factors could explain this response - including the women's strong motivation to improve their sex lives, improved communication with sexual partners, the presence of the patches as a visible reminder of the treatment's goal, and continuation of patterns of greater sexual activity that began when the women were receiving active doses. However, the higher testosterone dose improved sexual functioning and psychological well-being substantially more than did placebo treatment.
This study was part of a Phase II clinical development program for the testosterone patch conducted by Procter and Gamble Pharmaceuticals and Watson Laboratories. Enrollment is currently under way for a larger study of the patch at sites in the US, Europe and Australia. Women aged 20 to 70 who are experiencing impaired sexual functioning after surgical menopause and who would like information about participating in this study should call (877) 54WOMEN (877 549-6636) to see if they are eligible.
Co-authors of the NEJM article, in addition to Shifren and Mazer, are Glenn Braunstein, MD, of Cedars-Sinai Medical Center in Los Angeles; James Simon, MD, of Women's Health Research Center, Laurel, Maryland; Peter Casson, MD, and John Buster, MD, of Baylor College of Medicine, Houston; Geoffrey Redmond, MD, of the Foundation for Developmental Endocrinology in Cleveland; Regula Burki, MD, of Salt Lake City; Elizabeth Ginsburg, MD, of Brigham and Women's Hospital, Boston; Raymond Rosen, PhD, and Sandra Leiblum, PhD, of Robert Wood Johnson Medical School in New Jersey; and Kim Caramelli, MS, of Watson Pharmaceuticals-Utah. Additional authors were Kirtley Jones, MD, University of Utah Medical Center in Salt Lake City, and Clair Daugherty, MS, Anesta Corporation in Salt Lake City.
MGH website: http://www.mgh.harvard.edu
Watson Pharmaceuticals website: http://www.watsonpharm.com
Procter and Gamble Pharmaceuticals website: http://www.pgpharma.com
Journal
New England Journal of Medicine