Women suffering from low libido got some hope this week when a panel of health experts said the U.S. government should approve an experimental pill intended to boost sexual desire. It is the first time a government panel has endorsed such a drug. The move surprised many experts, because the Food and Drug Administration has twice rejected the drug due to lackluster effectiveness and worrisome side effects.
The FDA will make a formal decision later this summer. But many analysts say the panel’s backing could clear the way for the first drug approved to treat a female sexual disorder. Drugmakers have been trying to cultivate that market since the blockbuster launch of Viagra for men in the late 1990s. Ahead of this week’s meeting, women’s groups and other advocates lobbied for the pill’s approval, saying women’s sexual problems have been overlooked for too long by the federal government.
Here’s a look at the pill flibanserin from Sprout Pharmaceuticals, which some have dubbed “Female Viagra.”
How does the drug work?
Flibanserin acts on brain chemicals associated with mood and appetite, similar to antidepressant drugs. In fact, it was originally studied as a treatment for severe depression before being repurposed into a libido drug. It’s not entirely clear why flibanserin increases sexual desire but researchers point to its ability to increase dopamine — a brain chemical associated with appetite — while lowering serotonin — another chemical linked with feelings of satiation.
Who would take this drug?
Sprout wants to market the drug to premenopausal women with hypoactive sexual desire disorder, described as a lack of sexual appetite that causes emotional distress.
Surveys estimate that between 5.5 million to 8.6 million U.S. women have the condition, or roughly 8 to 14 percent of women ages 20 to 49. Because so many other factors affect sexual appetite there are a number of alternate causes doctors must rule out before diagnosing the condition, including relationship problems, medical conditions, depression and mood issues caused by other medications like sleeping aids and painkillers.
The diagnosis is not universally accepted and many psychologists argue that low sex drive should not be considered a medical condition.
Is the drug effective?
Experts usually describe flibanserin’s effect as “modest.” In company studies, women taking flibanserin reported a slight increase in sexually satisfying events each month. Their answers to separate questionnaires indicated they experienced a slight increase in desire and a slight decrease in stress.
While FDA scientists describe these effects as “small,” they were significant enough to meet FDA effectiveness standards.
The FDA panelists acknowledged this week that flibanserin will not help all patients. The percentage of patients reporting positive results with flibanserin was only 10 to 15 percent higher than among patients taking a placebo. That suggests as few as 1 in 10 patients may actually benefit from the drug, according to some FDA advisers.
What are the side effects?
Flibanserin’s side effects have hampered its review at the FDA for years. About 10 percent of patients in Sprout’s studies experienced the most common problems: dizziness, fatigue and nausea.
The FDA’s current review focuses on problems that are rare but more serious, including dangerously low blood pressure and fainting. Those problems appear to increase when patients drink alcohol or take certain other medications, including antifungal drugs.
If the drug is approved, FDA advisers said special steps should be considered to minimize these risks, including:
— A bold warning label not to drink or take certain other medications.
— Educational pamphlets for patients about the side effects to be distributed by pharmacists.
— Training requirements doctors must complete before prescribing the drug.
Why did the drug get a positive vote this time around?
In 2010, a similar panel of FDA experts unanimously voted against flibanserin, saying its benefits did not outweigh its risks. They noted the drug failed to achieve a key study goal — increasing desire based on daily journal entries. Since then, Sprout conducted another study of sexual desire using a different method that achieved statistical significance. The company also conducted several safety studies that shed more light on flibanserin’s interactions with alcohol and other drugs. The studies showed links to low blood pressure and fainting.
The company also enlisted support from members of Congress and women’s groups who met with the FDA and pushed for the drug’s approval.
All the panelists who voted for approval this week stressed that the FDA must require extra precautions to make sure the drug is used safely. They also said there is a need for FDA-approved therapies to treat women’s sexual problems. Currently many doctors prescribe drugs that are not intended to treat female desire disorder, including testosterone cream and various psychiatric drugs.
What happens now?
The FDA is expected to issue a ruling on flibanserin in August. TVJ
