Flibanserin

Flibanserin is indicated for premenopausal women with acquired, generalized hypoactive sexual desire disorder (HSDD), as characterized by low sexual desire that causes marked distress or interpersonal difficulty and is not caused by a coexisting medical or psychiatric condition, problems within the relationship, or the effects of a medication or other drug substance.

The mechanism of action of Flibanserin is not fully known. It is a postsynaptic serotonin-1A (5HT-1A) receptor agonist and 5HT-2A receptor antagonist. It may work by increasing dopamine and norepinephrine while decreasing serotonin in the brain's prefrontal cortex to enable sexual desire to manifest.

• Hypoactive Sexual Desire Disorder (HSDD): Indicated for premenopausal women with acquired, generalized HSDD characterized by low sexual desire that causes marked distress or interpersonal difficulty.

Serotonin-norepinephrine reuptake inhibitor (SNRI)

5-HT1A Agonist/5-HT2A Antagonist

The mechanism of action of Flibanserin is not known. Flibanserin demonstrated high affinity for 5-HTIA and 5-HT2A receptors, showing agonist activity on 5-HTIA and antagonist on 5-HT2A, resulting in lowering of serotonin in the brain as well as effect on increasing norepinephrine and dopamine neurotransmitters.

Flibanserin activates serotonin-1A receptors and blocks 5-HT2A receptors to increase dopamine and norepinephrine while decreasing serotonin, improving sexual desire.

Adult Dose (Oral):

• 100 mg PO once daily at bedtime.
• Discontinue after 8 weeks if no improvement.

Child Dose: Not recommended in patients below 18 years.

Take 100 mg tablet orally once daily at bedtime. Swallow it as a whole. Do not chew, crush or break it.

If you miss a dose of Flibanserin, take it as soon as possible; however, if it is almost time for your next dose, skip the missed dose.

Common Side Effects (>10%):

• Dizziness (11.4%)
• Somnolence (11.2%)
• Nausea (10.4%)

Uncommon Side Effects (1-10%):

• Fatigue (9.2%)
• Insomnia (4.9%)
• Dry mouth (2.4%)
• Anxiety (1.8%)
• Constipation (1.6%)
• Abdominal pain (1.5%)
• Metrorrhagia (1.4%)
• Rash (1.3%)
• Sedation (1.3%)
• Vertigo (1%)

Precautions:

• Coadministration with alcohol increases risk of severe hypotension and syncope (contraindicated).
• Coadministration with moderate or strong CYP3A4 inhibitors significantly increases flibanserin concentrations (contraindicated).
• Causes CNS depression (somnolence, sedation); risk increased if taken during waking hours, or with alcohol or other CNS depressants.
• Hypotension and syncope can also occur with flibanserin taken alone.
• Avoid activities requiring full alertness (operating machinery or driving) until at least 6 hours after each dose.

Contraindications:

• Use with alcohol
• Concomitant use with moderate or strong CYP3A4 inhibitors
• Any degree of hepatic impairment

Drug Interactions:

• Oral Contraceptives and Weak CYP3A4 Inhibitors: Increase flibanserin exposures and incidence of adverse reactions.
• Strong CYP2C19 Inhibitors: Increase flibanserin exposure (risk of hypotension, syncope, CNS depression).
• CYP3A4 Inducers: Substantially reduce flibanserin concentrations; use not recommended.
• Digoxin: Increases digoxin concentrations (may lead to toxicity); monitoring required.

Food Interactions: It is unsafe to consume alcohol with Flibanserin (risk of severe hypotension and syncope).

Use in Pregnancy: No studies in pregnant women; animal studies showed fetal toxicity only in presence of significant maternal toxicity.

Use in Lactation: Unknown if distributed in human breast milk; excreted in rat milk; breastfeeding not recommended during treatment due to risk of sedation in breastfed infant.

Pediatric Use: Not recommended in patients below 18 years.

Geriatric Use: Not indicated for use in geriatric patients; safety and effectiveness not established.

Renal Impairment: Limited information available; consult your doctor.

Hepatic Impairment: Contraindicated in any degree of hepatic impairment.

Overdose: Limited information on overdose; symptomatic treatment.

Storage: Keep below 30 degree C, away from light and moisture. Keep out of reach of children.

Flibanserin