June 17, 2010

Female Viagra Attempts Fall Short

The drug industry's latest attempt to find a female equivalent to Viagra fell short in two separate studies, according to federal regulators on Wednesday.

The Food and Drug Administration is considering Boehringer Ingelheim's drug flibanserin for pre-menopausal women who experienced a lack in sexual desire, a market that drug makers have been targeting for years since the epic success of Viagra for men.

The hunt for a female version of Viagra has proved elusive though, with many drugs failing after showing uninspiring results.

The FDA will ask a panel of experts on Friday to comment on the safety and effectiveness of Boehringer's drug. The agency is not required to heed the advice of the group, though it often does.

The FDA posted a review online saying two Boehringer studies failed to show a significant increase in sexual desire, as recorded by women in a daily journal. Women taking the drug reported a slight increase in sexual satisfaction, but the FDA said that was not the primary measure of the study.

"The division wanted to see that an effect of treatment is an overall increase in sexual desire regardless of whether a sexual event occurred or not," the FDA review stated.

The FDA said the drug also had increased side effects like depression, fainting and dizziness seen in women taking the pill. The pill also affects serotonin and several other brain chemicals, though the FDA is not clear on how that increases sex drive.

"We don't know specifically what the exact mechanism of action is but we believe it acts on brain chemicals that have a role in human sexual response," Dr. Peter Piliero, executive director for Boehringer's U.S. medical affairs, told the Associated Press (AP).

Dr. Elizabeth Kavaler, a urologist at Lenox Hill Hospital in New York, told AP that arousal in women is so complicated that it may be impossible to create a pill that will completely address all sexual problems.

"It's a fairly complicated area, unlike in men's sexual dysfunction where there's a major mechanical concern," said Kavaler. "In women there's no mechanical concern, so if she's not having a successful sex life, where is the problem?"

Pharmaceuticals took several approaches to boosting the female sex drive over the years. While many involved similar methods that Viagra uses, flibanserin is the first drug to approach the problem through brain chemistry.

Medical surveys have estimated more than 40 percent of women suffer from some form of sexual dysfunction. Boehringer estimates that as many as one in ten women could be helped by Flibanserin.

Boehringer zeroed in on the chemical aspect of sexual dysfunction by only testing its drug on pre-menopausal women who were in stable relationships and not taking other medications. Despite wanting to have a sexual relationship, the women enrolled in company studies reported a persistent lack of desire that caused them "distress or interpersonal difficulty."

Leonore Tiefer, a psychiatry professor at New York University who runs a private sex therapy practice, believes drug makers have oversimplified female sexuality. She told AP that in most cases lack of sex drive has more to do with the quality of one's relationship and lifestyle than brain chemicals.

During the public comment period during Friday's meeting, Tiefer will ask the FDA to reject the drug, arguing it offers insufficient benefits for women with unknown long-term risks.

Decision Resources analyst Alasdair Milton said he expects flibanserin sales to peak at $300 million after six or more years on the market. The male sexual dysfunction market was a 4.4 billion dollar industry last year, according to health care data firm IMS Health.


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