INTRODUCTION: Flibanserin, a novel 5-HT(1A) agonist and 5-HT(2A) antagonist, has 
the potential to treat sexual dysfunction.
AIM: Provide historical perspective on the rationale for development of 
flibanserin to treat sexual dysfunction, based on post hoc analyses of data.
MAIN OUTCOME MEASURES: The Arizona Sexual Experiences (ASEX) scale and the 
Hamilton depression rating scale (HAMD) Genital Symptoms item.
METHODS: Sexual function outcomes are presented from four double-blind, 
randomized controlled studies involving a total of 369 men and 523 women 
diagnosed with Major Depressive Disorder. Each study had an active treatment arm 
to confirm assay sensitivity on the primary antidepressive endpoint. Two studies 
placebo, flibanserin (50mg bid), or fluoxetine (20mg qd) for 6 weeks and two 
involved placebo, flibanserin (50-100mg bid), or paroxetine (20-40mg qd) for 8 
weeks.
RESULTS: Individual study completion rates were 77-80%. At baseline, 38% of men 
and 67% of women reported sexual dysfunction. Assay sensitivity was not 
demonstrated in the fluoxetine trials and sexual function outcomes were 
inconsistent. Flibanserin and placebo were associated with low rates of 
treatment-emergent sexual dysfunction in women during the paroxetine studies. In 
one study, 70% of flibanserin-treated women with baseline sexual dysfunction 
reported improvement in sexual function, compared with 30% of placebo-treated 
women. Mean change from baseline on the HAMD "Genital Symptoms" item in one 
paroxetine study was significantly better among flibanserin- than 
placebo-treated women at weeks 4, 6, and 8 (P<0.05). Sexual function adverse 
events across flibanserin groups were generally comparable to placebo.
CONCLUSIONS: Although these studies were not designed or powered to compare 
sexual function outcomes, results suggested a potential benefit of flibanserin 
on sexual function, particularly on female sexual desire, and provided a 
rationale to evaluate the efficacy of flibanserin as a treatment for female 
hypoactive sexual desire disorder.