Published on August 24, 2015

Viagra for women? Here’s what you need to knowViagra for women? Here’s what you need to know

On Aug. 18, the U. S. Food and Drug Administration approved the drug flibanserin for hypoactive sexual desire disorder, which the Mayo Clinic defines as women who are emotionally distressed by a lack of lust.

It’s catchy to call Sprout Pharmaceutical’s new drug “the female Viagra,” but it isn’t very accurate. Viagra works to correct erectile dysfunction in men. Its mission is physical: Send more blood to the penis to keep it erect.

Flibanserin, which will be marketed as Addyi, is more emotional: It works on neurotransmitters in women’s brains and changes levels of the brain chemicals serotonin, dopamine and norepinephrine.

And that means it’s a lot slower acting than Viagra. When men suffer from erectile dysfunction, they can take a pill about 45 minutes before they want to have sex.

Women have to take a pill every night and won’t see any results for four weeks, with optimal results occurring a few weeks after that.

The drug was studied in three randomized, double-blind, placebo-controlled tests on 2,400 women over a 24-week period. The results were a little underwhelming. On average, women taking flibanserin only experienced an increase of one sexual activity every two months.

The clinical tests specifically targeted pre-menopausal women who were in committed relationships, most for at least 10 years with reports of at least five years of loss of sexual desire. The average age of the participant was 36. The randomized trial focused on a narrow population that met a criteria of those most likely to benefit from the drug.

Randomized trials have their limitations. In this case, it is unknown how post-menopausal women will react to flibanserin. In fact, Sprout’s website specifically mentions that flibanserin is not designed for post-menopausal women, a group that accounts for many women with issues of decreased sex drive.

Sprout estimates that one in three women suffer from low sex drive. The drug is not appropriate for women with co-existing medical or psychiatric conditions such as depression, anxiety, mood or eating disorders. It also won’t help a bad relationship improve.

Additionally, it will not help those whose low libido is caused as a side effect of other medications such as selective serotonin reuptake inhibitors. A common side effect of SSRIs is low libido, but Sprout warns those taking them shouldn’t also take Addyi.

And for those who were wondering: The drug does not enhance sexual performance in any way. It seems to have a subtle effect on desire, but no one knows precisely how it works.

“Low sex drive is real,” says Phoebe Speck, PhD, a psychotherapist in Falmouth. “I have couples in here from teens through 80 that have problems in one way or another with sex drive. It’s a really common thing in marriage and there are all kinds of things that play into it.”

The brain, not blood flow

Ever since Pfizer introduced Viagra to the market in 1998, pharmaceutical companies have been searching for a female version that works as well. And why wouldn’t they? In 2012 the global erectile dysfunction market for pills like Viagra, Cialis, and more than two dozen other prescriptions that address erectile dysfunction in men raked in $4.3 million, according to a report by Transparency Market Research.

Pfizer actually spent eight years studying the effects of Viagra on 3000 women before abandoning the research in 2004. Even though Viagra enhanced blood flow to women’s genitals in a similar way that it does to men, it didn’t raise women’s levels of desire enough to work.

The conclusion was that women’s desire is enhanced by strong emotional connections. In other words, it’s the brain, not blood flow that counts.

The FDA had previously rejected flibanserin twice in the past, in 2010 and 2013. Both times the FDA decided that the results didn’t justify the side effects, which include fainting, dizziness, and drowsiness.

A national campaign of feminist groups funded by Sprout called Even the Score put pressure on both the FDA and politicians to approve the drug.

In June an advisory committee did just that, by a vote of 18 to 6, with the conditions that researchers work to minimize the side effects. The drug will also include a warning that the risks of side effects are greater when women drink alcohol or take anti-fungal medications.

Other risk factors are oral contraceptives, SSRIs, benzodiazepines and herbs like St. John’ Wort and gingko. Patients taking any of those items should not use flibanserin, which should be taken at night. Patients are advised not to drive for at least six hours after taking it.

All of these precautions make Mei Tsai uneasy.

“The benefits are very mediocre and the side effects are very high,” says Tsai, pharmacy clinical manager at Cape Cod Hospital, “The side effects are serious: hypotension, dizziness, syncope (temporary loss of consciousness due to low blood pressure) and a whole bunch of other things.

“I don’t know why anybody would want to take that kind of risk to take this drug where it’s not a life-threatening disease.”

Some said the FDA changed its mind because of political pressure; other say committee members were swayed after hearing some heart wrenching stories from women whose relationships were suffering greatly from a lack of sexual desire.

It remains to be seen how many women, and more importantly doctors, will sign on when Addyi becomes available in mid-October. Doctors’ acceptance is a key component.

To prescribe Addyi, doctors must enroll in an Addyi Risk Evaluation and Mitigation Strategy Program. Because of the possible risks, especially in connection with alcohol, both doctors and pharmacies must be certified to prescribe the med.

Addyi is expected to cost between $30 and $75 for women with health insurance, but there is some question about whether insurance will cover it.

Despite all the questions about Addyi, investors aren’t scared off. Two days after the FDA approval, Sprout announced a $1 billion deal with Valeant Pharmaceuticals, which who acquired Addyi on Aug. 20.