THURSDAY, Dec. 2, 2004 (HealthDayNews) -- U.S. health advisers late Thursday voted against approving a controversial testosterone patch for women struggling with diminished sex drives, citing the need for further safety studies.
The members of a U.S. Food and Drug Administration advisory panel said preliminary research only suggested modest benefits from the patch, called Intrinsa, which is designed for women who have had their ovaries removed, the Associated Press reported.
Panel members also expressed concerns about the potential health risks involving testosterone use.
Earlier in the day, the maker of the patch, Proctor & Gamble, told panel members at a hearing in Washington, D.C., that the drug had not been linked to any serious safety problems and asked that approval not be delayed because of an unknown risk, the AP said.
However, several members of the panel -- the FDA's Advisory Committee for Reproductive Health Drugs -- said they weren't satisfied with the number of women studied so far, and were also uncomfortable with the length of the clinical trials. They cited a lack of safety information for women who had used the patch longer than six months, the AP said.
The panel also heard testimony that three of four women who developed breast cancer during the trials were using the patch. Lisa Soule, a medical officer in FDA's division of reproductive and urological drugs, said those reports of breast cancer underscored the limitations of short-term clinical trials, the news service reported.
Intrinsa would have been the first FDA-sanctioned drug designed to address women's sexual problems. But the drug's potential use has already triggered sharp clashes between supporters and opponents.
The FDA panel hearing marked the "first time that the government has acknowledged the existence of women's sexual health issues and is thinking of pharmaceutical solutions to deal with it," said Dr. Irwin Goldstein, a professor of urology and gynecology at Boston University and director of its Institute for Sexual Medicine.
He believes that drugs such as Intrinsa would "empower women to ask their doctors about care, and finally motivate researchers to better understand the physiology of what happens when a woman has sexual dysfunction."
But another expert in female sexual health, New York University professor of psychiatry Lenore Tiefer who was slated to address the FDA panel, took a different view.
"I think it [testosterone therapy] is dangerous. We just don't know a lot about it," she said. Tiefer pointed to the checkered history of estrogen supplementation, where long-term use of the hormone was linked to increases in risk for heart disease and breast cancer. Sales of hormone replacement therapy plummeted following the release of that data.
"We have a lot of scary history here with long-term hormone use," Tiefer said, "and whatever studies we have now on testosterone for women were short-term. It turns out that hormones have effects in the long term that they don't have in the short term."
Testosterone is most commonly thought of as a male hormone, but in fact "it's in the body, physiologically, in all women," Goldstein explained. He said animal studies began to suggest decades ago that declining levels of testosterone might translate to lowered libido in females. Subsequent research has supported the idea that raising testosterone not only increased female sexual desire, but also the more physiologic aspects of sex -- genital lubrication, swelling, and even the quality and frequency of orgasms, Goldstein said.
Goldstein said he and many of his colleagues in the field of sexual health have been prescribing supplemental testosterone to their female patients for years.
"Low sexual interest translates, in many women's lives, to bother and distress," he said. "Sex, if it is performed, is done out of obligation, out of guilt. It becomes just another chore. The patient feels she's not who she was, that she's communicating the wrong message to her partner, and she has low self-esteem, or becomes depressed."
Goldstein said "thousands" of women treated at his Boston clinic over the years have been helped by testosterone therapy. "They really appreciate it," he said.
He agreed there is a lack of data on the safety of long-term testosterone in women. But he said the wait for that data shouldn't preclude prudent use of testosterone in women today.
"We've only had Viagra out for seven years," he noted. "Should we have waited for 20 years of Viagra data and not allowed its use?"
But Tiefer said any comparison between Intrinsa with Viagra misses the point, since Viagra leaves the system a few hours after use, whereas the testosterone patch is designed to emit a steady level of the hormone over time. "With hormones, you have to take them weeks or months before they even begin to have an effect," she said.
As part of the approval process, Procter & Gamble submitted the results of two studies involving almost 1,100 women who had had their ovaries and uteri removed for medical reasons. One study found that, compared to women on placebo, women using Intrinsa experienced a 56 percent rise in sexual desire and a 74 percent rise in satisfying sexual encounters -- working out to about one additional sexual episode per woman per month.
"So it's one event per month," Tiefer said. "That's not insignificant, but to me it's outweighed by the worries I have about the dangers of long-term testosterone." She also worries about off-label use of the drug, with doctors potentially prescribing it to young women, pregnant or nursing women, or other types of patients not yet included in clinical trials.
Dr. Sidney Wolfe, director of the nonprofit consumer advocacy group Public Citizen, echoed that sentiment. In a statement, his group "strongly opposes [FDA] approval of this testosterone patch based on safety concerns."
But Goldstein believes testosterone supplementation has already been helping thousands of women battle -- and defeat -- a problem that they've long been told was all in their head.
"The data epidemiologically shows that 43 percent of American women have this problem" at some point in their lives, he said.
To learn more female sexual dysfunction, visit the National Library of Medicine.