Flibanserin (Addyi), released in 2015, is FDA-approved for Hypoactive Sexual Desire Disorder in premenopausal women (it has not been tested in men or postmenopausal women). It was originally developed as an antidepressant.
Addyi has been colloquially referred to as the “female Viagra”, but it has nothing in common with Viagra (sildenafil). Its mechanism involves dopamine, norepinephrine, and serotonin (5-HT).
Physicians had to be certified to prescribe Addyi, but this restriction was lifted in 2019. Originally women taken Addyi were expected to abstain from alcohol because the combination can cause severe hypotension/syncope. In 2019 the contraindication with alcohol was softened. Addyi is contraindicated with liver impairment and with (strong to moderate) 3A4 inHibitors. These contraindications all relate to increased risk of hypotension/syncope and are all presented as black box warnings.
Women taking flibanserin reported an increase in “satisfying sexual events” from 2.8 to 4.5 events per month. Women taking placebo improved from 2.7 to 3.7 events per month.
Flibanserin has turned out to be a flop of a medication, with only about 5,000 annual prescriptions. Its lack of popularity is unsurprising given its disappointing efficacy, costs, and (previously) mandated alcohol abstinence pledge. In 2019 the label warning for alcohol use was softened to state “women should discontinue drinking alcohol at least two hours before taking Addyi at bedtime or skip the Addyi dose that evening. Women should not consume alcohol at least until the morning after taking Addyi at bedtime”.
For context, blocking 5-HT2A is the opposite of what hallucinogens do. LSD is a 5-HT2A agonist. Second generation antipsychotics also block 5-HT2A—2A for 2nd gen Antipsychotic.
Dosing: The starting and maintenance dose is 100 mg QD HS.