‘Female Viagra’ FDA Approval: 5 Facts Women Should Know About Flibanserin

A Food and Drug Administration panel recommended a drug called flibanserin -- dubbed the “female Viagra” -- for approval this week. But experts say the comparison to the erectile dysfunction medication is problematic and gives the wrong impression to women seeking treatment for sexual problems.

“I think it’s a catastrophe. It's a superficial, quick-and-dirty term,” says Dr. Leonore Tiefer, a psychologist at New York University School of Medicine who attended yesterday’s FDA hearing. “Any drug that's going to be proposed for female sexual problems is going to be called female Viagra because of the wild success of Viagra, but it's so different.”

Flibanserin, which will be marketed under the name Addyi, treats hypoactive sexual desire disorder (HSDD), which the Mayo Clinic defines as a low sex drive that causes personal distress. For women who are interested in the drug, there are important factors to keep in mind:

The drug doesn’t work like Viagra. Flibanserin treats women through a completely different mechanism than the way that Viagra works in men. Viagra increases blood flow to the genitals to help men achieve an erection, while flibanserin affects the central nervous system.

“Flibanserin is a drug that works on the brain,” Dr. Stanley Althof, executive director at the Center for Marital and Sexual Health of South Florida, says. “It works to increase dopamine and deal with two different forms of serotonin.”

Tiefer likens it to an antidepressant. In fact, the drug was initially tested as an antidepressant before researchers realized that it might have pro-sexual effects.

It doesn’t work right away. The effects of Viagra on men are seen almost instantly since it boosts blood flow directly to the penis. But women who took flibanserin every day in a trial did not see any benefits over a placebo until four weeks after they started treatment. Tiefer says “peak results” did not come until eight weeks after patients started the regimen.

Unlike Viagra, which is taken only when needed and works within 45 minutes, flibanserin must be taken every day and is not an instant fix.

The drug isn’t meant for all women who have a low sex drive. The drug’s maker, Sprout Pharmaceuticals Inc., says flibanserin may be used to treat up to 16 million women in the U.S. – one in 10 – who are distressed by their low sex drive. This is a subset of the total women who experience a low sex drive, which Sprout estimates is about one in three.

Althof says many women who have low desire may benefit more from other approaches such as making lifestyle changes that reduce stress, halting their use of antidepressants or participating in relationship counseling. In fact, he typically explores all these options with a patient before diagnosing HSDD.

Also, the women who participated in the clinical trials for flibanserin were married for an average of 10 years and had suffered from HSDD for a long time – about five years. Women who experience occasional short bouts of low desire may not be good candidates for the new treatment.

It isn’t that effective. Women who took flibanserin in trials reported having an average of 4.4 satisfying sexual sessions a month versus 3.7 sessions among those who took a placebo and 2.7 for women before participating in the study.

“Viagra and the drugs like Viagra -- Cialis, Levitra -- all have a very robust response in the majority of men,” Althof says. “This drug, flibanserin, has a modest response.” That mediocre result was part of the reason two previous FDA panels rejected applications for the drug’s approval.

However, Althof points out that women afflicted with HSDD who gain just one more satisfying session a month might find these results to be worthwhile. “Everybody else looks at this through their own lens,” he says.

There are still safety concerns about the drug. Though flibanserin earned a recommendation for FDA approval from a joint committee meeting on Thursday, all the panelists who cast a “yes” vote also warned that Sprout would need to develop a program to mitigate the risks of the drug, which include fainting, nausea and low blood pressure, beyond simply labeling them as side effects.

The dangers also prompted the National Women’s Health Network to oppose the drug’s approval at the hearing. It’s not yet clear whether these concerns will limit usage of the drug or stop doctors from prescribing it for all but the most critical cases.

“If it's approved, there are going to be all kinds of cautions put on it – ‘Don't take with alcohol, don't take with a long list of prescription medications,’ ” Tiefer says.

The FDA must still grant its final approval before the medicine may be prescribed to patients. That official stamp of approval could come as early as August.