Flibanserin

GENERIC AVAILABLE: No

Flibanserin can cause low blood pressure and fainting. Therefore, flibanserin should not be combined with alcohol and other drugs that also cause low blood pressure.

Flibanserin is metabolized or broken down by liver enzymes. Drugs that induce the activity of these enzymes will decrease blood levels of flibanserin. Examples of such drugs include

• carbamazepine (Tegretol),
• rifampin (Rifadin),
• St. John's Wort,
• phenobarbital, and
• several other drugs.

Flibanserin should not be combined with drugs that decrease its blood levels.

Drugs that block the action of enzymes that breakdown flibanserin will increase blood levels and side effects of flibanserin. Therefore, flibanserin should not be combined with

• itraconazole (Sporanox),
• clarithromycin (Biaxin),
• ketoconazole (Nizoral),
• fluconazole (Diflucan),
• ritonavir (Norvir),
• indinavir (Crixivan),
• telithromycin (Ketek),
• diltiazem (Cardizem),
• verapamil (Calan),
• grapefruit juice, and
• other drugs that may increase its blood levels.

Flibanserin increases blood levels of digoxin (Lanoxin). This may lead to digoxin toxicity.

Common Side Effects of Flibanserin

Tell your doctor if any of the following side effects become severe or don't go away:

• Dizziness
• Nausea
• Sleepiness
• Insomnia
• Dry mouth

Serious Side Effects of Flibanserin

Tell your doctor right away if you experience any of the following serious side effects:

• Fainting or loss of consciousness
• Severe dizziness or sleepiness
• Signs of very low blood pressure (may include lightheadedness, nausea, clammy skin, blurry vision, depression, or dizziness)

Addyi, known as the "female Viagra", is a prescription medication used to enhance sexual desire and decrease emotional distress in premenopausal women with hypoactive sexual desire disorder (HSDD). 

This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.

Before taking flibanserin tell your doctor about all of your medical conditions. Especially tell your doctor if you:

• are allergic to flibanserin or to any of its ingredients
• drink alcohol, use drugs, or have a history of alcohol or drug abuse
• have ever had depression or other mental health problems
• have low blood pressure or a medical condition that can cause low blood pressure
• are pregnant or plan to become pregnant. It is not known if flibanserin will harm your unborn baby.
• are breastfeeding or plan to flibanserin. It is not known if flibanserin passes into your breast milk. You and your doctor should decide if you will take flibanserin or breastfeed. You should not do both
• have liver problems

Tell your doctor about all the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements.

Tell your doctor if you are breastfeeding or plan to breastfeed.

It is not known if flibanserin crosses into human milk. Because many medications can cross into human milk and because of the possibility for serious adverse reactions in nursing infants with use of this medication, breastfeeding is not recommended during treatment with flibanserin.

Skip the missed dose and take the medicine the following day at bedtime. Do not take flibanserin in the morning, and do not take extra medicine to make up the missed dose.

Do not drink alcohol while taking flibanserin. Drinking alcohol with this medicine can cause dangerous or unwanted side effects.

Grapefruit and grapefruit juice may interact with flibanserin and lead to unwanted side effects. Avoid the use of grapefruit products while taking flibanserin.

Avoid taking an herbal supplement containing: ginkgo, resveratrol, or St. John's wort.

Flibanserin may impair your thinking or reactions. Avoid driving or operating machinery for at least 6 hours after you take flibanserin, and until you know how this medicine will affect you. Dizziness or low blood pressure can cause falls or other accidents.

Avoid getting up too fast from a sitting or lying position, or you may feel dizzy. Get up slowly and steady yourself to prevent a fall.

Usual Adult Dose for Hypoactive Sexual Desire Disorder:

100 mg orally once per day at bedtime

Duration of therapy: This drug should be discontinued after 8 weeks if the patient does not report an improvement in symptoms.

Comments: This drug is not indicated to enhance sexual performance, and is not indicated for treatment in postmenopausal women or in men.

Use: Treatment of 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 due to a co-existing medical or psychiatric condition, problems within the relationship, or the effects of a medication or other drug substance.

Contraindications

• Alcohol use.1 (See Boxed Warning and also see Hypotension and Syncope with Alcohol under Cautions.)

• Concurrent use of moderate or potent CYP3A4 inhibitors.1 (See Hypotension and Syncope with CYP3A4 Inhibitors under Cautions and also see Interactions.)

• Hepatic impairment.1 (See Hypotension and Syncope in Patients with Hepatic Impairment under Cautions.)

Warnings/Precautions

Warnings

Concomitant use of flibanserin and alcohol increases the risk of severe hypotension and syncope.1 Syncope requiring therapeutic intervention (e.g., ammonia salts and/or placement in supine or Trendelenburg position), hypotension, and somnolence occurred at a higher incidence when flibanserin was administered with alcohol in the morning during an alcohol interaction study.1

Alcohol use is contraindicated in patients taking flibanserin.1 Before prescribing flibanserin, the clinician must assess the likelihood of the patient abstaining from alcohol, taking into account the patient's social and medical history, including current and past drinking behavior.1 (See Boxed Warning and also see Specific Drugs and Foods under Interactions.)

Moderate or potent CYP3A4 inhibitors substantially increase flibanserin exposure and the risk of hypotension and syncope; therefore, concomitant use of flibanserin and moderate or potent CYP3A4 inhibitors is contraindicated.1

If treatment with a moderate or potent CYP3A4 inhibitor is required, discontinue flibanserin at least 2 days prior to initiation of therapy.1 If the benefit of initiating therapy with a moderate or potent CYP3A4 inhibitor within 2 days of flibanserin discontinuance clearly outweighs the risk of hypotension and syncope, monitor patient for signs of hypotension and syncope.1 Allow at least 2 weeks to elapse between discontinuance of the CYP3A4 inhibitor and reinitiation of flibanserin therapy.1

Concomitant use of flibanserin with multiple weak CYP3A4 inhibitors, including dietary or herbal supplements (e.g., ginkgo, resveratrol) and OTC drugs (e.g., cimetidine), also may increase flibanserin exposure and lead to hypotension and syncope.1 (See Interactions.)

Use in patients with any degree of hepatic impairment substantially increases flibanserin concentrations, which can cause hypotension and syncope.1 Flibanserin is therefore contraindicated in patients with hepatic impairment.1 (See Absorption: Special Populations, under Pharmacokinetics.)

Other Warnings and Precautions

Risk of somnolence and sedation when given alone;1 CNS depressant effects are most prominent approximately 1–4 hours after oral administration.9

Risk of CNS depression is increased if flibanserin is taken during waking hours, with alcohol or other CNS depressants, or with drugs that increase flibanserin concentrations (e.g., CYP3A4 inhibitors).1 (See Dosage and Administration, Interactions, and Advice to Patients.)

Use of flibanserin alone can cause hypotension and syncope.1 In controlled studies of premenopausal women with HSDD, hypotension and syncope were reported in 0.2 and 0.4% of flibanserin-treated patients, respectively.1 The risk of hypotension and syncope is increased if taken during waking hours or in higher than recommended dosages.1

Consider the clinical benefits of flibanserin therapy and the risks of hypotension and syncope in patients with preexisting conditions that predispose to hypotension.1 (See Warnings under Cautions.)

If presyncope occurs, patient should immediately lie supine and promptly seek medical attention if symptoms do not resolve.1 If syncope occurs, patient should promptly obtain medical attention.1

Dose-related increase in incidence of malignant mammary tumors observed in female mice at exposures 3 and 10 times those attained with recommended human dosage; effect not observed in male mice or in male or female rats.1 Clinical relevance not known.1

Specific Populations

No studies to date in pregnant women.1 In animal studies, fetal toxicity occurred only in conjunction with substantial maternal toxicity (e.g., reduced weight gain, sedation).1 Decreased fetal weight, structural abnormalities, and increases in fetal loss occurred at exposures >15 times those achieved with recommended human dosage.1 Manufacturer states that animal studies cannot exclude potential for fetal harm.1

Distributed into milk in rats; not known whether distributed into human milk.1 Because of the potential for serious adverse reactions, including sedation, in nursing infants, breast-feeding during flibanserin therapy not recommended.1

Not indicated for pediatric patients.1

Not FDA labeled for use in geriatric patients; safety and efficacy not established.1 Manufacturer states not indicated for treatment of HSDD in postmenopausal women†.1 (See Absorption: Special Populations, under Pharmacokinetics.)

Contraindicated in patients with hepatic impairment.1 (See Hypotension and Syncope in Patients with Hepatic Impairment under Cautions and also see Absorption: Special Populations, under Pharmacokinetics.)

Exposure only increases slightly in patients with mild to severe renal impairment.1 Dosage adjustment unlikely to be necessary.1 (See Absorption: Special Populations, under Pharmacokinetics.)

Peak plasma concentrations and AUC are increased and elimination half-life is prolonged in poor CYP2C19 metabolizers compared with extensive CYP2C19 metabolizers.1 (See Pharmacokinetics.) Increased monitoring for adverse effects (e.g., hypotension) recommended.1 Approximately 2–5% of Caucasians and Africans and approximately 2–15% of Asians are poor CYP2C19 metabolizers.1

Common Adverse Effects

Dizziness,1 somnolence,1 nausea,1 fatigue,1 insomnia,1 dry mouth.1 Most of these adverse effects began during first 14 days of therapy.1

If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

(flib AN ser in)

Commonly reported side effects of flibanserin include: syncope, central nervous system depression, dizziness, drowsiness, fatigue, nausea, sedation, and hypotension. Other side effects include: insomnia. See below for a comprehensive list of adverse effects.

Data not available.