Female Viagra approved by FDA

The first drug to treat sexual dysfunction in premenopausal women - dubbed the "female Viagra" - has received approval from the US Food and Drug Administration.

Flibanserin has been approved by the FDA to treat premenopausal women with low sexual desire.
Image credit: G. Breed/Associated Press

Manufactured by Sprout Pharmaceuticals, Flibanserin (brand name Addyi) has been given the green light by the federal drug agency for the treatment of hypoactive sexual desire disorder (HSDD) - a condition characterized by low sexual desire.

It is estimated that around 1 in 10 women develop HSDD, and up to 40% experience the condition at some point in their lives. Psychological factors, such as low self-esteem, stress or mental health problems may contribute to low sexual desire, as well as hormone changes or physical factors, such as fatigue or lifestyle habits.

While the exact mechanisms by which flibanserin works is unclear, Sprout Pharmaceuticals believe it corrects an imbalance in brain chemicals that are responsible for sexual desire.

The US Food and Drug Administration (FDA) say a 100-mg dose of the drug should be taken once daily just before bedtime. Patients should discontinue use if they experience no improvement in sexual desire within 8 weeks.

Today's approval provides women distressed by their low sexual desire with an approved treatment option.

The FDA strives to protect and advance the health of women, and we are all committed to supporting the development of safe and effective treatments for female sexual dysfunction.

Flibanserin only to be prescribed by certified health care professionals, pharmacies

The FDA reached their decision by conducting an analysis of three randomized, double-blind, placebo-controlled trials involving around 2,400 women of an average age of 36 years who had HSDD.

For a 24-week period, the women took either a placebo or a 100-mg dose of flibanserin before bedtime. The women who took flibanserin reported a modest increase in sexual desire and the number of sexual events during the study period, as well as a reduction in distress as a result of low sexual desire.

On assessing the safety of the drug, the FDA report the most common adverse reactions identified were nausea, dizziness, fatigue, sleepiness, insomnia and dry mouth.

However, the organization notes flibanserin is also associated with hypotension - severely low blood pressure - and loss of consciousness, particularly if taken with alcohol. Such side effects have led the FDA to reject the drug twice previously - once in 2010 and again in 2014.

As such, their approval of flibanserin comes with a risk evaluation and mitigation strategy (REMS), which requires that all prescribers enroll in and complete a training program before treating patients with the drug.

Because of a potentially serious interaction with alcohol, treatment with Addyi will only be available through certified health care professionals and certified pharmacies. Patients and prescribers should fully understand the risks associated with the use of Addyi before considering treatment.

In addition, a Boxed Warning is being applied to flibanserin, informing patients about the risk of hypotension and concussion if taken with alcohol, as well as warning patients with liver impairment or those taking moderate or strong CYP3A4 inhibitors to avoid use of the drug.

The FDA also require that Sprout Pharmaceuticals carry out three well-designed studies in order to further assess the health risks associated with flibanserin on interaction with alcohol.

FDA approval likely to attract mixed reactions

While many women and health care professionals may welcome the FDA's decision to approve flibanserin, others are likely to have concerns.

While the FDA's approval of flibanserin comes with conditions reflecting their safety concerns, the decision has still been met with criticism, with one health expert hailing it a "sad day for drug regulation."

This opens the way for drug companies to pressure the FDA through public relations campaigns to approve more bad drugs: It's bad news for rational drug approval.

References:

1.  FDA news release, accessed 19 August 2014.
2.  Sprout Pharmaceuticals news release, accessed 19 August 2015.
3.  Additional source: SexHealthMatters, Overview - HSDD, accessed 19 August 2015.
4.  Additional source: Mayo Clinic, Low sex drive in women, accessed 19 August 2015.
5.  Additional source: The Washington Post, FDA approves controversial drug for women with low sex drives, accessed 19 August 2015.