Plenty of women probably rue the day the little blue impotence pill was approved, but drug companies think the desire for sex is just as important to women as the ability to have sex is to men. And several are trying to introduce drugs to treat female sexual dysfunction.
So women, brace yourselves! But don't get too excited. While drug treatments are on the way to help renew ladies' lustful longings, they aren't for all females. And unlike Viagra, most aren't intended to directly improve physical performance. Rather, the libido enhancers are for those who have lost the desire for sex, often as a result of menopause or the removal of ovaries.
HORMONE SHIFT. What exactly is female sexual dysfunction? Most sex therapists now classify it as a lack of desire for sex -- often to such a degree that the affected women don't have sex at all -- or a physical dysfunction that makes sex unbearably painful. Researchers believe that low or absent libido is often caused by a shift in hormone levels. The male hormone testosterone is believed to be a main driver of not just the male libido but of the female's as well. In women who have gone through menopause or who have had their ovaries removed, testosterone production falls off dramatically.
According to a recent survey conducted by the AARP, lack of sexual desire is the most common sexual problem reported by women, yet the majority of the women interviewed said a satisfying sex life is important to them. Unlike many of their mothers, Baby Boom women, who are now middle-aged, consider sex vital to their well-being. "Women of this generation are accustomed to being sexual," says Dr. Philip Sarrel, professor of psychiatry and obstetrics and gynecology at Yale University. "It's already very common and meaningful, and will become more so. With the massive wave of women entering [middle age], the need for treatment is even greater."
While lack of libido takes the forefront in women's sexual anxieties, only 7% of women interviewed in the AARP study said they had tried taking medicine to enhance sexual performance. Of those, the majority said the treatments they tried increased sexual satisfaction. But the potential market of women who could benefit from such treatment is substantial. About 35 million women worldwide have had their ovaries removed while 99 million in the U.S. and Western Europe alone are naturally menopausal.
CATCHING ON. The U.S. Food & Drug Administration hasn't cleared any product to specifically treat female sexual dysfunction. And hormone replacement therapies, which are frequently given to menopausal women and those who have had their ovaries removed, can come with side effects and complications. "Generally speaking, there's a hurdle to hormone therapy," says Ian Sanderson, an analyst at SG Cowen. "You have to convince women that uterine and breast cancer are not a big risk. And with testosterone, women would be worried about side effects."
EstraTest, a pill that contains both estrogen and synthetic testosterone, has been on the market for more than 30 years as a hormone replacement therapy. But it will likely be the first to get FDA approval specifically to increase women's libido. In the last five years, sales of the drug have grown rapidly as doctors have begun to catch on that the pill increases desire, says Roland Gerritsen van der Hoop, vice-president for clinical operations at Solvay, which makes the pill. The Belgian drugmaker is finishing a late-stage trial of 220 patients in the U.S. and expects to release the data in the next several months.
As a libido-enhancing drug, "it will probably have a carryover effect on to performance," van der Hoop says. The amount of testosterone in EstraTest is low, but it still causes a low incidence of "masculinizing" side effects like deepening of the voice and growth of facial and body hair, as well as acne.
PATCH, NOT PILL. Procter & Gamble (PG
) is working on a transdermal testosterone patch with Watson Pharmaceutical (WPI
). The companies are completing Phase II testing and plan to start a large-scale trial early next year. The product would be used in normal hormone replacement therapy, which typically includes a combination of female hormones, says Marlene Feder, a spokeswoman for P&G Pharmaceutical. "The beauty of the dosing system is that it can deliver testosterone and bring women back to premenopausal levels," she says. "And since it's in patch form, not all of the testosterone passes through the skin and becomes available in the blood stream all at once."
Mark Nixon, assistant professor of obstetrics and gynecology at the University of Massachusetts, Worcester, has seen mixed results with testosterone products. "I've found postmenopausal women have not always done so well. Some have mood disturbances. But others feel like initiating sex and feel better overall."
And the erection-causing drug Viagra may have a place in treating women. Women have some erectile tissue in the vaginal area. Increasing blood flow to this tissue with Viagra could cause arousal in women, much as it does to men. Pfizer (PFE
), which sold $1.3 billion worth of Viagra last year, has conducted several Phase II studies of the drug's effects in women. It appears safe, but women didn't feel significantly aroused. "It's too soon to say that Viagra doesn't work in women. Our research is ongoing. We're hopeful we will find a population of women who will respond to Viagra," says Geoff Cook, spokesman for Pfizer.
HUSHED DISCUSSION. Finding a benefit in women is becoming a matter of increasing importance to Pfizer as serious rivals to Viagra are starting to emerge. ICOS Corp. (ICOS
) and partner Eli Lilly (LLY
), are planning to file Cialis, which the company says has fewer side effects than Viagra for erectile dysfunction, with the FDA later this year (see BW Online, 4/13/01, "Viagra May Soon Be Facing a Rival"). The company is also testing Cialis in women. "We thought that increasing blood flow in women could be useful," says Lisa Fitzpatrick, a spokeswoman at ICOS.
While more and more women are talking to their doctors about their lack of interest in sex, it's still a hushed discussion for many. But that's beginning to change as women who came of age during the Sexual Revolution begin to face the issue. "Because it's an undertreated area, there are definitely a lot of complaints. There's definitely a therapeutic need," van der Hoops says. We may be a long way from Viagra for women, but don't be surprised if women's appetites increase as more treatments reach the market. Tsao covers biotechnology for BusinessWeek Online in New York