Addyi — The “Female Viagra” Dr. Peter Rice explains



A few weeks ago, the Food and Drug Administration (FDA) approved a little pink pill that patients call “viagra for women”.

The approval of Addyi™ (brand name) or flibanserin (generic name) followed a lobbying campaign by Sprout Pharmaceuticals, and by a group called ‘Even the Score’. The drug provides an interesting picture into the drug development and approval process.

Addyi (flibanserin) is not “viagra” at all, but is a new type of drug for the treatment of hypoactive sexual desire disorder (HSDD) in women. HSDD is defined by the American Psychiatric Association as “persistently or recurrently deficient or absent sexual fantasies and desire for sexual activity” along with “marked distress and interpersonal difficulty” that is not attributed to other conditions.

Flibanserin failed to show activity when first studied as an antidepressant, but patient responses suggested that it might increase sex drive in some patients. The drug was reviewed by the FDA in 2009 and again in 2013; each time it was turned down by the FDA because the balance of benefit versus risk was not deemed to be favorable enough.

Ask your doctor about Addyi

Ask your doctor about Addyi

Over the years, and prior to the development of hypoactive sexual desire disorder as a disease, I have encountered several strategies to improve female libido. Sexual lubricants can increase female interest in sex; their use was not allowed in the flibanserin studies because they might skew the results. Testosterone products and Viagra (sildenafil) have been used, but were never deemed effective enough to secure FDA approval for HSDD.

Flibanserin was studied in two clinical trials, called BEGONIA and SNOWDROP. In the BEGONIA study, 543 premenopausal women took 100mg of drug for 24 weeks and found an average of one additional ‘satisfying sexual event’ per month compared to patients taking an inactive placebo. In the SNOWDROP study, 468 postmenaopausal women (average age 55) experienced a less dramatic 0.4 additional ‘satisfying sexual events’ per month. In each study there were also questionnaire responses indicating positive effect from the medication, but only about 10% over that for the inactive placebo.

 


Addyi is indicated for premenopausal women with HSDD.

It is not indicated for postmenopausal women or for men. It is taken as a 100mg tablet at bedtime. Patients should avoid alcohol while taking Addyi, as it can lead to hypotension and fainting. The most common adverse effects were sleepiness, dizziness, nausea and headache; these seemed to occur more frequently in premenopausal women taking oral contraceptives.

When first reviewed by the FDA, the concern was whether the drug was really effective; the manufacturer measured changes in sexual desire using two different tools, and the one presented at first did not show the drug to be effective. When reviewed again by the FDA, a different measurement was presented showing the drug to be effective, but safety concerns remained. Most recently, additional safety data was presented and the FDA panel recommended approval with special safeguards to minimize the risk to patients.

So, flibanserin is now FDA-approved with the brand name Addyi  for treatment of premenopausal women with HSDD.

The lobbying campaign that preceded FDA approval for Addyi cited gender-inequality and noted that the FDA had approved many drugs for sexual dysfunction in men, but had not yet approved a single drug for women. I’m not sure I buy the sexism argument; men also have something to gain from a drug increasing female sexual desire.

 

The approval of Addyi raised some additional issues.

  1. Some have questioned whether hypoactive sexual desire disorder is a disease developed by the drug manufacturer just to promote this new drug.
  2. Others note that the effectiveness is marginal; compared to inactive treatment, only about 10% more women reported “meaningful benefit” from the drug.
  3. This may mean that it works particularly well, but only for a small percentage of women; and many women will experience the adverse effects without any benefit from the drug.
  4. The FDA panel was also concerned that Addyi use would not be limited to the premenopausal patient population for which it was approved.

 

If you’re considering taking Addyi, talk with your prescriber or pharmacist and consider the benefits and risks of the drug for you. As with all new drugs, much will be learned as Addyi is used in more and more patients.

References:

  1. http://www.sproutpharma.com/sprout-pharmaceuticals-receives-fda-approval-addyi-flibanserin-100-mg/
  2. http://www.drugs.com/history/addyi.html
  3. http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm458734.htm
  4. http://uchealth.com/wp-content/uploads/2013/12/Menopause-Efficacy-and-Safety-of-Flibanserin-in-Postmenopausal-Women-w-.pdf
  5. http://www.issm.info/news/sex-health-headlines/flibanserin-hsdd-and-the-begonia-trial
Dr. Peter J. Rice

About Dr. Peter J. Rice

Dr. Peter J. Rice is a professor of Pharmacology emeritus at the East Tennessee State University Quillen College of Medicine and Professor of Clinical Pharmacy at the University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences. --------------------------------------------------------------------------He received his BS in pharmacy from Northeastern University, PhD in pharmacology from the Ohio State University and PharmD from the University of Kentucky. He is a Board Certified Pharmacotherapy Specialist and practices in the ambulatory care and community pharmacy settings. Professor Rice is the author of Understanding Drug Action: An introduction to pharmacology (APhA, 2014) and is a fellow of the American Pharmacists Association. --------------------------He welcomes interesting medication questions and suggestions for future columns.
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