A Drug for Arousal
It's not just men who want some help with sexual performance
The ink had barely dried on the Food and Drug Administration's approval of Viagra when women began asking, "What about us?" Nearly seven years after the drug hit the market, Cialis and Levitra have also been OK'd for men, but there is still nothing for women. The wait appeared to be over late last year when an FDA advisory committee studied Intrinsa, a testosterone patch backed by promising studies. But the committee recommended against approval.
Those who voted down Intrinsa worried about the drug's possible long-term side effects, an understandable concern following news of ill effects from female hormones and Vioxx. But the ongoing Intrinsa story raises other questions, too: What, really, is female sexual dysfunction? Are drugs a good way to treat it? Was Intrinsa held to a different standard because the drug is intended for women?
Intrinsa is not a female Viagra. Indeed, there will probably never be the equivalent of that drug for women. Sexual dysfunction in men is mostly the inability to get and maintain an erection throughout intercourse. By contrast, there is no precise definition for female sexual dysfunction. It includes disorders of desire and arousal, difficulties in achieving orgasm, pain tied to intercourse, and disgust at the thought of sex. In fact, many argue that a woman's sexual dysfunction (FSD in the jargon) can't be analyzed as simply a medical issue--that beliefs from her upbringing and the quality of her relationships are just as influential as biology.
Rekindling romance. Whatever the definition of FSD, the most common sexual complaint doctors hear from women is one of low libido, or, as it's called in medicalese, hypoactive sexual desire disorder. Though many things, from not enough sleep to screaming kids, can dampen desire, one hormonal suspect is a lack of testosterone. Though it's thought of as a male hormone, testosterone is found in women, too, albeit at much lower levels; the ovaries and adrenal glands split the task of making it. Testosterone influences desire in both sexes, so it is used to rekindle a low libido.
Kathy Kelley runs Hystersisters.com, a support website for women who have undergone hysterectomies and removal of the ovaries. While some women actually report increased libido after surgery, others feel a slow and distressing decline. For these women, the usual advice to "spice things up" isn't adequate, Kelley says. "The doctor pats you on the head and says, 'Run down to Victoria's Secret,' " she adds. Many women have already discovered testosterone, in off-label use of products intended for men and in Estratest (a combination of estrogen and testosterone intended to relieve menopausal symptoms) or formulations compounded at pharmacies.
In the Intrinsa trials, women whose ovaries were removed and who took the drug reported a higher number of satisfactory sexual events (a placebo worked well, too, but not as well as the drug). A majority of the advisory panel members agreed there was a benefit, but they worried about long-term safety, especially when Intrinsa is taken in combination with estrogen replacement therapy. The risks they were concerned about--breast cancer and heart disease--would probably not show up for years, indicating that those who review clinical trials have become much more conservative in the post-hormone-replacement-therapy, post-Vioxx era. "It appears that the rules are changing," says Stephen Simes, president and CEO of BioSante, who expects to begin human trials of the testosterone gel Libigel this year. "Traditionally, we've always thought of 12 months as [the period for] safety studies," he says. The FDA "may make it 18 months, but if it's beyond three or four years, that's not practical." For its part, Procter & Gamble, the developer of Intrinsa, is talking with the FDA about what data it must provide to satisfy the agency's safety concerns.
Some breast-cancer experts echo the committee's concerns. Others agree with the decision but not for the FDA's reasons. Leonore Tiefer, a psychologist at NYU School of Medicine, worries about off-label use. She fears that female sexual dysfunction might be overdiagnosed and that drugs would become a quick fix, especially given P&G's marketing muscle.
Those disappointed by the decision make two points. They say the legitimate questions about direct-to-consumer marketing by drug companies and overmedicalization are larger issues and ones to which Intrinsa's fate should not be hitched. If it works, women who need it deserve the choice now. "Women are smart enough to know if this is applicable to them," says Elaine Plummer, a P&G spokesperson.
Sex bomb. They also question the consistency of the FDA's approval process. Viagra was approved after trials of six months, despite the fact that the FDA knew beforehand that it is dangerous for patients taking nitroglycerin. Testosterone products for men were approved after reviews of similar length, even though there have been no long-term studies of their effects and even though they may promote prostate cancer. Is a sex drug aimed at benefiting women perceived as less valuable than one aimed at men?
The questions are not going away. Unless the FDA, in the post-Vioxx era, is prepared to impose vastly more stringent trial requirements on drug makers, some testosterone product aimed specifically at women with low libido will eventually be approved. Other companies with their own versions of testosterone products are on P&G's heels, and until these drugs reach the market, off-label use will continue. Drugs for arousal disorder are also in the pipeline (Viagra itself was once studied for this). "In a certain way, the train has already left the station," says Tiefer. Or, as Sheryl Kingsberg, a clinical psychologist at the Case Western Reserve University School of Medicine who is involved in the drug's trials, puts it: "Intrinsa was the first hope but not the only hope."
This story appears in the January 24, 2005 print edition of U.S. News & World Report.