'Female viagra' approved by regulators in the US
The first prescription drug designed to boost sexual desire in women has been approved by regulators in the US.
The move by the Food and Drug Administration (FDA) was a milestone long sought by a pharmaceutical industry eager to replicate the blockbuster success of impotence drugs for men.
But stringent safety measures on the daily pill called Addyi mean it will probably never achieve the sales of Viagra, which has generated billions of dollars since the 1990s.
The drug's label will bear a boxed warning - the most serious type - alerting doctors and patients to the risks of dangerously low blood pressure and fainting, especially when the pill is combined with alcohol.
The same problems can occur when taking the drug with other commonly prescribed medications, including antifungals used to treat yeast infections.
"Patients and prescribers should fully understand the risks associated with the use of Addyi before considering treatment," said Dr Janet Woodcock, director of the FDA's drug centre.
Under an FDA-imposed safety plan, doctors will only be able to prescribe Addyi after completing an online certification process that requires counselling patients about Addyi's risks.
Pharmacists will also need certification and will be required to remind patients not to drink alcohol while taking the drug.
Opponents of the drug say it is not worth the side effects, which also include nausea, drowsiness and dizziness. They point out that the FDA rejected the drug twice, in 2010 and 2013, due to these risks.
"This is not a drug you take an hour before you have sex. You have to take it for weeks and months in order to see any benefit at all," said Leonore Tiefer, a psychologist and sex therapist who organised a petition last month calling on the FDA to reject the drug.
Patients should stop taking the drug after eight weeks if they do not see any improvement, notes the FDA release.
Sprout Pharmaceutical's drug is intended to treat women who report emotional stress due to a lack of libido. Its approval marks a U-turn by the FDA, which previously rejected the drug twice due to lacklustre effectiveness and side effects.
The decision represents a compromise of sorts between two camps that have publicly feuded over the drug for years.
On one side, Sprout and its supporters have argued that women need FDA-approved medicines to treat sexual problems. But safety advocates and pharmaceutical critics warn Addyi is a problem-prone drug for a questionable medical condition.
Beginning with the drug's launch in October, doctors who see patients complaining about a loss of sexual appetite will have a new option.
"Women are grasping, and I feel like we need to offer them something that acknowledges that, and that we can feel safe and comfortable with," said Dr Cheryl Iglesia, a surgeon and official with the American Congress of Obstetricians and Gynecologists.
The search for a pill to treat women's sexual difficulties has been something of a holy grail for the pharmaceutical industry.
It was pursued and later abandoned by Pfizer, Bayer and Procter & Gamble, among others. But drugs that act on blood flow, hormones and other biological functions all proved ineffective.
Addyi, known generically as flibanserin, is the first drug that acts on brain chemicals that affect mood and appetite.
Women and their doctors will have to decide whether the drug's modest benefits warrant taking a psychiatric pill on a daily basis.
Company trials showed women taking the drug generally reported one extra "sexually satisfying event" per month, and scored higher on questionnaires measuring desire.
Ms Tiefer and other critics said the FDA was pressured into approving the drug by a feminist-themed lobbying campaign funded by Sprout and other drugmakers.
For now, executives at Sprout, based in Raleigh, North Carolina, are setting modest expectations for Addyi, their first and only product. The company will focus its 200 sales representatives on promoting the drug to medical specialists.
Women with insurance can expect to pay between 30 dollars (£19) and 75 dollars (£47.86) per month for Addyi.
The FDA specifically approved the drug for premenopausal women with hypoactive sexual desire disorder, a lack of sexual appetite that causes distress.
Surveys estimate that 8 to 14% of women ages 20 to 49 have the condition, or about 5.5 to 8.6 million US women.
Because so many factors affect sexual appetite, there are a number of alternate causes doctors must rule out before diagnosing the condition, including relationship issues, medical problems, depression and mood disorders.
The diagnosis is not universally accepted, and some psychologists argue that low sex drive should not be considered a medical problem.