Flibanserin

Flibanserin (BIMT-17) is a drug produced by Boehringer Ingelheim. It is currently being investigated as a drug for women with decreased sexual desire. It is a 5-HT1A serotonin receptor agonist, a 5-HT2A serotonin receptor antagonist, and a dopamine D4 receptor partial agonist that had initially been developed as an anti-depressant. As with Viagra, the effects of flibanserin were discovered serendipitously after it was trialled as an antidepressant.

Early results
On November 16, 2009, Boehringer Ingelheim reported that late-stage trials showed that the drug promoted sexual desire and increased the number of "satisfying sexual events" in women suffering from abnormally low libido.

The results of four Phase III studies involving more than 2,000 pre-menopausal woman suffering from so-called Hypoactive Sexual Desire Disorder (HSDD) were presented at the congress of the European Society for Sexual Medicine in Lyon, France. Women with the drug said that the average number of times they had "satisfying sexual experiences" rose from 2.8 to 4.5 times a month. However, women with the placebo said the number of times rose to 3.7 times a month. Flibanserin must be taken once a day and takes up to 4 weeks to have an effect. In animals, flibanserin increases dopamine and noradrenalin and decreases serotonin.

Mechanism of action
Flibanserin directly manipulates the chain of chemical reactions in the brain believed to trigger sexual desire. This is unlike Procter & Gamble's hormone patch Intrinsa, which is targeted at post-menopausal women.

Clinical trials
As of November 2009, Phase III clinical trials are assessing safety and efficacy in pre- and post-menopausal women.