Immediately after Flibanserin (Addyi) was approved by the FDA in September for the treatment of acquired hypoactive sexual desire disorder (HSDD), my phone started ringing with patients requesting prescriptions and information about this drug. There is a lot of hype and enthusiasm for Flibanserin and many media outlets have touted it as the new ‘pink Viagra’.
Enthusiasm for research and drug development for female sexual dysfunction is warranted as the market has been hyper-focused on male dysfunction thus far, and the market has seemingly ignored that most men have sex with women, and these women also need to have treatments for sexual dysfunction for couples to truly have a healthy and fulfilling sex life.
So is this new ‘pink Viagra’ going to revolutionize the sex lives of many women, in a similar way that Viagra has for men? No, not at all. To understand why, let’s first do a brief review of the medication’s development, how it works (or does not), how it is used and the negative side effects.
How was the drug developed?
Flibanserin was first developed as an antidepressant. Its developmental origin has nothing to do with sex. It failed as an antidepressant so a secondary market was sought to try to recoup the costs of the drug’s development by Boehringer. The drug works by altering levels of serotonin and dopamine, both of which are thought to play a role in sexual desire, so a use for HSDD was sought. The drug failed FDA approval for HSDD in 2009 and 2013, due to it not really working well and safety concerns. During this time, Sprout bought the drug and did more studies and sought approval again. The FDA approved it in September 2015 with the conditions of a risk evaluation and mitigation strategy (REMS), black box warning for low blood pressure, fainting and additional post-marketing research. It is anticipated to be available to patients in October under strict regulations.
How does the drug work?
Flibanserin works centrally. That means it works on the brain and the chemical balance in the brain. It does NOT work directly on the genitals and exactly how it works to improve sex drive is not fully understood. This is in direct contrast to Viagra for men. Viagra’s mechanism is well understood, and it works directly on tissues in the penis to facilitate engorgement and the physical ability to have sex with an erection. Viagra is not intended to treat decreased libido and is not related to psychiatric drugs. In the studies that gained FDA approval for Flibanserin, it outperformed the placebo by one satisfying sexual experience (SSE) per month. That is, sex one more time a month compared to the placebo. That is not much, but some argue if you go from sex once a month to twice a month that is significant; but to be clear, it is not causing women to want to have sex daily or even weekly. “Will it turn me into a rabbit?” one patient asked me. No, it will not. In addition, unlike Viagra which is used around the immediate time of sex as needed, Flibanserin has to be taken EVERY DAY whether or not you intend to have sex that day or week.
Are there negative side effects?
Part of the reason that Flibanserin was denied twice by the FDA is its negative side effects. It has the potential to cause severe hypotension (low blood pressure), and this is made worse by any consumption of alcohol. So if you use it, you must fully abstain from alcohol all the time; which is not a reasonable trade-off for many women. It also has the potential to cause syncope (fainting). Because of the way the liver metabolizes the drug, there are a lot medications that can’t be taken with it, such as reflux medications, certain antidepressants, yeast infection treatments and others. Physicians who prescribe it must do specific training to be allowed to prescribe it, and patients must sign a patient contract acknowledging the risks of the drug. Additionally, the population I see that struggles the most with HSDD is postmenopausal women, and Flibanserin is approved for pre-menopausal women and not post-menopausal women.
So have we caught up with the boys in the field of sexual medicine with Flibanserin? My answer is not at all. I think it will be very hard to find patients who are great candidates for Flibanserin, given all of the above. However, there may be select pre-menopausal women who are willing to adhere to all the restrictions and tolerate the side effects to give it a go. Despite the many short-comings of this new treatment for HSDD, I am encouraged by a few things:
1: The pharmaceutical companies are beginning to investigate women’s sexual health as a real area of drug research and development.
2: The media and patient-driven excitement over the drug will likely foster more research into the area as there is a proven market that is eager to purchase drugs.
3: The study that led to the FDA’s approval saw an improvement in SSE’s of 1.5 per month even in the placebo group (2.5 in the Flibanserin group), which means that likely just talking about and thinking about improving your sex life has a positive effect.
4: Patients will hopefully be prompted to raise concerns about their sex lives with their doctors as a result of hearing about Flibanserin in the media and from friends.
5: Flibanserin’s media splash and our patients’ enthusiasm for its success will undoubtedly raise the awareness of more doctors and practitioners of how important a healthy sexual life is to many women and that we need to be more proactive in screening our patients for HSDD.
In summary, Flibanserin is not ‘Pink Viagra,’ but it has people talking about women’s sexual health. Importantly, there are a number of other strategies available to improve women’s sex life that we can use today until the pharmaceutical market gets a little more “rosy” in the HSDD therapy arena.
Rosanna Gray-Swain, MD, is a member of BJC Medical Group and a part of the West End OB-GYN practice. The practice is located at 1110 Highlands Plaza, Suite 280, St. Louis, MO and can be reached at 314-286-2620.