Viagra-like pill for women fails in 2 studies

WASHINGTON -- The first pill designed to boost the female sex drive failed to make a significant impact on libido in two studies, federal health regulators said, though some women did report slightly more sexually satisfying experiences

The Food and Drug Administration is considering Boehringer Ingelheim's drug flibanserin for premenopausal women who report a lack of sexual desire, a market that drugmakers have been targeting for more than a decade since the blockbuster success of Viagra and similar drugs in men.

On Friday, the FDA will ask a panel of experts to advise on the safety and effectiveness of Boehringer's drug. The agency is not required to follow the group's advice.

In its review posted online Wednesday, FDA said 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 slightly more sexually satisfying experiences, but 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 said.

The FDA also noted increased side effects like depression, fainting and dizziness among women taking the pink pill.

The drug, which is related to the antidepressant family, affects serotonin and several other brain chemicals, though it's not clear 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," said Dr. Peter Piliero, executive director for Boehringer's U.S. medical affairs.

Since the launch of Viagra in 1998, more than two dozen experimental therapies have been studied for so-called "female sexual dysfunction," a market some analysts estimate at $2 billion.

Dr. Elizabeth Kavaler, a urologist at Lenox Hill Hospital in New York, said arousal in women is so complicated that it may be unrealistic to expect a pill to completely address sexual problems.