Flibanserin Dosing

The recommended dosage of flibanserin (Addyi) is 100 mg taken orally once daily at bedtime. 1

Standard Dosing Regimen

Flibanserin must be taken at bedtime because administration during waking hours significantly increases the risks of hypotension, syncope, accidental injury, and central nervous system depression (including somnolence and sedation). 1
The dose is 100 mg once per day, with no dose titration required or recommended. 1
If a dose is missed at bedtime, the patient should take the next dose at bedtime the following day—do not double the dose. 1

Discontinue flibanserin after 8 weeks if the patient does not report improvement in symptoms, as continued treatment is unlikely to provide benefit. 1
Treatment may be continued long-term in patients who respond, as flibanserin may be used for a decade or more in typical premenopausal patients with HSDD. 2

Patients must wait at least 2 hours after consuming 1-2 standard alcoholic drinks before taking flibanserin at bedtime, or skip the dose entirely if they have consumed 3 or more drinks that evening. 1
After taking flibanserin at bedtime, patients should not consume alcohol until the following day. 1
The combination of flibanserin and alcohol close in time dramatically increases the risk of severe hypotension and syncope. 1

Flibanserin is absolutely contraindicated with moderate or strong CYP3A4 inhibitors (such as ketoconazole, itraconazole, clarithromycin, nefazodone, ritonavir, and many others), as these increase flibanserin concentrations and can cause severe hypotension and syncope. 1
If initiating flibanserin after stopping a CYP3A4 inhibitor, wait 2 weeks after the last dose of the inhibitor. 1
If initiating a CYP3A4 inhibitor after flibanserin, wait 2 days after the last dose of flibanserin. 1

Flibanserin is contraindicated in patients with any degree of hepatic impairment (mild, moderate, or severe), as flibanserin exposure increases 4.5-fold in these patients, dramatically increasing the risk of severe hypotension and syncope. 1

CYP2C19 poor metabolizers require increased monitoring for adverse reactions (especially hypotension), as they have increased flibanserin exposures compared to extensive metabolizers. 1
CYP2C19 poor metabolizers represent approximately 2-5% of Caucasians and Africans, and 2-15% of Asians. 1

Flibanserin treatment results in approximately 0.5-1 additional satisfying sexual event per month compared to placebo. 3, 4
Improvements in sexual desire (FSFI desire domain) and reduction in distress (FSDS-R-13) are statistically significant but modest, with mean improvements of 0.3-0.9 points on validated scales. 3, 4
Women's global impression of improvement scores indicate minimal improvement to no change on average. 4

The most common adverse events include:

Dizziness (risk ratio 4.00 vs placebo) 4
Somnolence (risk ratio 3.97 vs placebo) 4
Nausea (risk ratio 2.35 vs placebo) 4
Fatigue (risk ratio 1.64 vs placebo) 4
Insomnia (7.7% in postmenopausal women) 5
The risk of study discontinuation due to adverse events is more than doubled (risk ratio 2.19) compared to placebo. 4

Flibanserin is FDA-approved only for premenopausal women with acquired, generalized hypoactive sexual desire disorder (HSDD). 1
It is not indicated for postmenopausal women or men, though some research suggests potential efficacy in postmenopausal women. 1, 5
Flibanserin is not indicated to enhance sexual performance—it specifically treats HSDD characterized by low sexual desire causing marked distress that is not due to other medical/psychiatric conditions, relationship problems, or medication effects. 1
Breastfeeding is not recommended during treatment due to potential for serious adverse reactions including sedation in breastfed infants. 1