Nov. 19, 2009 -- An investigational drug that didn't perform well as an
antidepressant appears to slightly boost sexual desire as well as the
number of satisfying sexual encounters in women with lagging libidos, a study
The research was presented this week at the 12th Congress of the European
Society for Sexual Medicine in Lyon, France.
Some wonder if the drug, called flibanserin, will be the new ''female
Viagra," but critics say the effect is minimal. Meanwhile, the manufacturer is
planning additional clinical trials and expanding the participant pool to
include older women.
The big news, according to those who studied flibanserin? "There is
something that works on the neurotransmitters in the central nervous system to
alter sexual desire in a positive way," says John M. Thorp Jr., MD, McAllister
distinguished professor of obstetrics and gynecology at the University of North
Carolina at Chapel Hill School of Medicine, and a principal investigator for
the U.S. trials.
At the Congress, researchers reported the pooled results for 1,378
premenopausal women, average age 35, who took 100 milligrams of the drug or a
placebo pill during a 24-week period. The trials were in Europe and North
America. The women kept track of the number of satisfying sexual encounters --
defined as intercourse, oral sex, masturbation, or genital caressing by their
partners. All women had to be in a stable, monogamous relationship. All women
had a diagnosis of hypoactive sexual desire disorder (HSDD), marked by a
decrease or absence of sexual desire accompanied by distress in the
When researchers compared sexual desire and events during the last four
weeks to the first four weeks, they found that those on the medication went
from 2.8 sexually satisfying events in the first four weeks to 4.5 in the final
four weeks. Those on placebo went from 2.7 to 3.7.
''The difference was [about] one additional satisfying sexual encounter a
month," says Thorp.
The study also shows the drug improved sexual functioning and distress
related to the sexual problems.
About 15% of the women taking the medication dropped out due to adverse
events, according to information from Boehringer Ingelheim Pharmaceuticals,
which makes the medications, while 7% of women on placebo discontinued the
study. Among the most commonly reported side effects were daytime sleepiness,
dizziness, anxiety, and fatigue.