Taking Sides: Should ob/gyns prescribe flibanserin for their patients?
Yes. It is effective for many women with hypoactive sexual desire.
By Holly L Thacker, MD
Dr Thacker is Professor and Director, Center for Specialized Women’s Health at Cleveland Clinic, Ohio, and Executive Director of Speaking of Women’s Health.
Sexual concerns are common in women and ob/gyns are in the best position to advise them about these problems. Until recently, physicians and their female patients have had only unregulated or unapproved and/or off-label treatment options with unclear benefit/risks ratios for sexual concerns. In 2015, the Food and Drug Administration (FDA) approved flibanserin as a first-in-class medication for hypoactive sexual desire disorder (HSDD), based on results from 3 pivotal trials.
When your patients have symptoms of HSDD, what do you do? Are you “certified” to prescribe flibanserin? If you are not yet certified, I believe you should be. After excluding medical, psychological and relationship problems, and medication side effects, I do not hesitate to prescribe flibanserin 100 mg at bedtime to appropriate patients in my practice. It has been studied in and proven to work in both premenopausal and postmenopausal women2 although it is currently only FDA-approved for pre-menopausal women. It works for a good number of patients, that is, at least 50% have a meaningful response.
Flibanserin was initially studied as an antidepressant (with effects on depression similar to paroxetine) and the finding that it improved sexual desire was serendipitous. It is a 5-hydroxytryptophan (1A) receptor agonist and 5-hydroxytryptophan (2A) receptor antagonist that restores sexual desire by rebalancing brain chemistry. It is not an aphrodisiac and must be taken over time to be effective.
Many FDA-approved medications such as sildenafil approved for male erectile dysfunction, ospemifene approved for vulvovaginal atrophy and dyspareunia, and flibanserin approved for HSDD were initially studied for other conditions (cardiac indications, osteoporosis, and depression, respectively) and found to have advantageous sexual side effects.
In cases in which flibanserin (Addyi) fails to improve sex drive after 2 months, it can be abruptly discontinued without harm. The discontinuation rate of 12%–13% based on central nervous system (CNS) side effects is in line with that of other drugs affecting the CNS. Data from the pivotal trials with bedtime dosing showed that approximately 11% of flibanserin-treated women experienced somnolence and/or dizziness compared to the 2%–3% of placebo controls.1
Flibanserin’s side effects—dizziness, hypotension, and somnolence—are also in line with many CNS antidepressants that we prescribe to women for conditions that include depression, anxiety, and premenstrual dysphoric disorder, with which ob/gyn physicians are already familiar. These risks can be reduced by taking the medicine at night and avoiding alcohol, which can raise flibanserin blood levels.
A recent article in JAMA Internal Medicine may cause some physicians to think twice about prescribing this drug, which is the only FDA-approved medication for women with HSDD. I find fault with both the biased meta-analysis3 and the biased editorial4 by an anti-pharma husband-and-wife couple, who took the FDA to task for approving the medication after its third submission.
I question the JAMA editorial staff as to why the meta-analysis3 was not more carefully vetted before being accepted for publication, particularly when a 2015 meta-analysis of all randomized, double-blind, placebo-controlled studies of flibanserin showed it to be effective in the treatment of HSDD.1 In all 4 trials, flibanserin was superior to placebo in increasing satisfying sexual events (SSEs), sexual desire scores, and ratings on the Female Sexual Function Index. The proportion of women who experienced an adverse event, nervous system disorder, or fatigue indicated that flibanserin was well tolerated.