Most women with low sexual desire won't rush to get the first prescription drug to boost female libido when it becomes available on Saturday. But they may have more options down the road.
Addyi is a daily medication and cannot be taken with alcohol or certain other medications, which will likely limit its use. But experts believe those restrictions could spur development of better treatments for women's sexual problems after more than a decade of neglect by most of the world's large drugmakers.
Kim Wallen, a psychology professor at Emory University, says Addyi represents a historic milestone that may open the door to more drugs targeting desire in men and women. Where Viagra and other men's erectile dysfunction drugs work by increasing blood flow to the genitals, Addyi acts on brain chemicals associated with desire.
"This is the first time that a drug, for either men or women, has been approved strictly to increase sexual desire," Wallen says. "That legitimizes many other drugs that are in development."
Treatments for women's libido issues are an untapped financial opportunity for drugmakers. Analysts estimate the market could be worth over $2 billion, based on academic estimates that between 5 million and 9 million U.S. women may suffer from desire disorders.
But the area hasn't been a research priority for drugmakers in many years. Beginning in the 1990s, Pfizer, Bayer and Procter & Gamble all studied — then discarded — drugs targeting female libido.
Addyi itself was developed by the German conglomerate, Boehringer Ingelheim, then sold to Sprout Pharmaceuticals after the Food and Drug Administration rejected the medication due to lackluster effectiveness and issues like nausea, fatigue and dizziness.
It took Sprout four years to win FDA approval for Addyi, which acts on brain chemicals associated with mood and appetite. The drug will come with a bold warning label about the risks of fainting if combined with alcohol or certain medications. Additionally, doctors and pharmacists must complete an online certification process to show they understand the drug's risks.
Dr. Lisa Dabney says several patients have asked her about Addyi, but they generally lose interest after she explains they cannot drink alcohol while taking the daily medication.
"It's definitely an option that's going to help patients," says Dabney, of New York's Mt. Sinai hospital. "But it's going to have a limited patient audience because of the alcohol restrictions and the fact that you have to take it every day."
Experts generally describe Addyi's effect as "modest." In company studies, women taking the drug that's also called flibanserin reported a slight uptick 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.
Analysts from Evercore ISI estimate Addyi could generate sales of $200 million annually. That's far below the blockbuster numbers once discussed by experts and the $1 billion that Valeant Pharmaceuticals recently agreed to purchase Sprout.