LOS ANGELES -- According to a study published in the Sept. 7 issue of the New England Journal of Medicine, an experimental testosterone patch improved the sexual function and psychological well-being of women who had undergone surgical menopause (removal of the ovaries and uterus).
Seventy-five women between ages 31 and 56 enrolled in the study, the first ever conducted with a testosterone skin patch to treat sexual problems in surgically menopausal women, according to Glenn D. Braunstein, M.D., Chair of the Department of Medicine at Cedars-Sinai Medical Center. Of the original 75 participants, 18 withdrew or were removed from the study because of personal, medical or compliance issues.
Cedars-Sinai was one of nine participating research centers in the United States.
Despite receiving estrogen replacement therapy, many women whose ovaries are surgically removed experience decreased sexual desire, activity and pleasure, and they have a reduced sense of general well-being. The ovaries produce about half of the testosterone that circulates in the bloodstream of premenopausal women, with the other half contributed by the adrenal glands.
Each of the women in the study had had both ovaries and her uterus removed before natural menopause, at least one year but not more than 10 years earlier. All of those qualifying to participate expressed dissatisfaction with their sexual function and had low scores on a standardized measurement of female sexuality.
After screening and a four-week base-line period, the women participated in three consecutive 12-week treatment periods, receiving two abdominal patches that were changed twice a week. The sexual functioning questionnaire and an assessment of psychological well-being were repeated at the end of the initial four-week base-line period and at the end of each 12-week treatment period.
During one treatment phase, both patches were inactive (placebo), containing no testosterone. During another 12-week period, one patch was active and the other was inactive, thereby providing a low dose of testosterone. In the other phase, both patches contained testosterone and therefore provided a greater dose. All of the experimental patches looked the same and neither the participants nor the investigators knew the content of the patches at any given time. Also, the women continued on the estrogen replacement therapy they were taking previously.
To be sure the treatment was safe, patients were monitored for changes in laboratory values, facial and body hair growth, and acne. Hormone levels were measured regularly, and the skin was assessed to determine the local tolerability of the patches.
Overall, the results showed that testosterone levels increased to within normal ranges and was well tolerated. Treatment with the higher dose of testosterone improved sexual function and psychological well-being substantially more than placebo, although there was a noted placebo effect.
"The placebo had a markedly positive effect, on average, as far as the instrument that we used, looking at such factors as libido, sexual activity, pleasure and orgasm," said Dr. Braunstein. "This was more apparent in younger women than in older women. When we did the statistical analysis, the placebo effect tended to reduce the overall significance of the findings for the entire group, although we did find significance with the higher dose patch. When we looked at the data of the older patients alone, the placebo effect was markedly reduced and we could see a dose response between the two doses of testosterone that were used."
Dr. Braunstein said a significant placebo effect is not unexpected in this type of study, and the researchers can only speculate as to why it exists and why it was generally more striking among younger participants. Factors might include the fact that all of the women in the study wanted their sex lives to be more active or satisfying; participation in the study may have facilitated communication within couples; the younger women had been in shorter relationships than the older women and may have felt greater pressure to improve their sexual functioning; and some couples may have altered their patterns of sexual activity early in the study and then maintained the new patterns throughout.
"I think it is multi-factorial," Dr. Braunstein said. "Just getting involved in the study and putting a patch on may change the individual if they think that they're getting an active ingredient. They may be more receptive to sexual activity. Also, because sex generally is a two-way street, their spouse or significant other -- and they had to be in a monogamous relationship to be in the study -- may have been excited by the fact that their partner was interested in improving their sex life. That in and of itself may have been enough to stimulate sexual activity."
Dr. Braunstein said that although this Phase II study is completed, a larger one has been launched that is being conducted at more centers and is using different testing instruments to measure sexual function. Following that study, a larger yet Phase III clinical trial will likely be required before the Food and Drug Administration approves the testosterone patch for general treatment.
This study was supported by funding from Procter & Gamble Pharmaceuticals of Cincinnati, Ohio, and Watson Pharmaceuticals, Inc., of Corona, Calif.
For media information and to arrange an interview, please call 310-423-4039 or 310-423-4767. A full-text version of this news release, plus other news information from Cedars-Sinai Medical Center, is available on Newswise at http://www.newswise.com and on EurekAlert at http://www.eurekalert.org
For more information on the study, please call 1-877-54WOMEN 8-8 Eastern, Monday-Friday.
Journal
New England Journal of Medicine