flibanserin

Absorption: Moderately absorbed (33%) following oral administration.

Distribution: Unknown.

Protein Binding: 98%.

Metabolism/Excretion: Primarily metabolized in the liver, via the CYP3A4 isoenzyme, and to a lesser extent by the CYP2C19 isoenzyme; the CYP2C19 isoenzyme exhibits genetic polymorphism; poor metabolizers may have significantly ↑ flibanserin concentrations and an ↑ risk of adverse effects. 44% excreted in urine, 51% in feces almost entirely as metabolites, which do not appear to be pharmacologically active.

Half-Life: 11 hr.

Time/Action Profile ⬆ ⬇

(plasma concentrations)

ROUTE	ONSET	PEAK	DURATION
PO	within 1 hr	1 hr	24 hr

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity;
Concurrent use of strong/moderate CYP3A4 inhibitors;
Hepatic impairment;
Lactation: Lactation.

Use Cautiously in:

Alcohol ingestion within 2 hr of flibanserin dose (excess risk of hypotension/syncope);
CYP2C19 poor metabolizers (↑ risk of adverse reactions including hypotension, syncope, and drowsiness);
OB: Safety not established in pregnancy.

Adv. Reactions/Side Effects ⬆ ⬇

CV: HYPOTENSION/SYNCOPE

Derm: rash

GI: nausea, constipation, dry mouth

Neuro: dizziness, drowsiness, anxiety, fatigue, insomnia, vertigo

Misc: HYPERSENSITIVITY REACTIONS (INCLUDING ANAPHYLAXIS AND ANGIOEDEMA)

Interactions ⬆ ⬇

Drug-drug:

Concurrent use of strong or moderate CYP3A4 inhibitors, including atazanavir, ciprofloxacin, clarithromycin, conivaptan, diltiazem, erythromycin, fluconazole, fosamprenavir, itraconazole, ketoconazole, nelfinavir, posaconazole, ritonavir, and verapamil, significantly ↑ levels and the risk of toxicity; concurrent use contraindicated. Wait 2 wk after discontinuing inhibitor before initiating flibanserin. If initiating inhibitor, wait two days after last dose of flibanserin.
Concurrent use with alcohol↑ risk of hypotension/syncope and excess sedation; wait ≥2 hr after consuming 1–2 standard alcoholic drinks before taking dose at bedtime; skip bedtime dose if consumed ≥3 standard alcoholic drinks.
Concurrent use of oral hormonal contraceptives and weak CYP3A4 inhibitors including cimetidine, and fluoxetine may ↑ levels and the risk of toxicity; avoid concurrent use with multiple weak CYP3A4 inhibitors.
Strong CYP2C19 inhibitors, including proton pump inhibitors, SSRIs, benzodiazepines, and antifungals, ↑ levels and the risk of toxicity; concurrent use should be undertaken with caution.
CYP3A4 inducers, including carbamazepine, phenobarbital, phenytoin, rifabutin, rifampin, and rifapentine, ↓ levels and effectiveness; concurrent use not recommended.
↑digoxin and sirolimus levels and the risk of toxicity; careful monitoring recommended
↑risk of CNS depression with other CNS depressants, including alcohol, antihistamines, opioids, sedative/hypnotics, some anti-anxiety agents, antidepressants, and antipsychotics.

Natural-Natural Products:

Concurrent use with gingko may ↑ levels and the risk of toxicity; avoid use with other weak CYP3A4 inhibitors.
St. John's wort↓ levels and effectiveness; concurrent use not recommended.

Drug-Food:

Grapefruit juice↑ levels and the risk of toxicity; concurrent ingestion contraindicated.

Route/Dosage ⬆ ⬇

PO (Adults ): 100 mg once daily at bedtime.

Availability ⬆ ⬇

Assessment ⬆ ⬇

Assess sexual desire and related distress and interpersonal dysfunction before and periodically during therapy.
Monitor for hypotension and syncope. Have patient lie supine if dizziness occurs.
Assess likelihood of patient following alcohol restrictions, taking into account the patient’s current and past drinking behavior, and other pertinent social and medical history. Counsel patients who are prescribed flibanserin about the importance of following guidelines for alcohol use; interaction with alcohol increases risk of hypotension and syncope.

Implementation ⬆ ⬇

Administer once daily at bedtime; administration during waking hr increases risks of hypotension, syncope, accidental injury, and CNS depression.

Patient/Family Teaching ⬆ ⬇

Instruct patient to take flibanserin only at bedtime as directed. If dose is missed, omit and take next dose at bedtime on next day. Advise patient to read Medication Guide before starting therapy and with each Rx refill in case of changes.
Advise patient to avoid grapefruit juice during therapy.
Caution patient to follow alcohol guidelines during therapy. Wait at least 2 hr after drinking 1 or 2 standard alcoholic drinks (one 12-oz regular beer; 5 oz of wine; 1.5 oz or a shot of brandy, gin, rum, tequila, vodka, or whiskey) before taking flibanserin at bedtime. If you drink 3 or more standard alcoholic drinks in the evening, skip your flibanserin dose at bedtime. After you have taken your flibanserin at bedtime do not drink alcohol until the following day. Alcohol increases hypotensive effects. May cause dizziness and fainting.
Advise patient if dizziness occurs, immediately lie supine and promptly seek medical help if symptoms do not resolve.
May cause drowsiness. Caution patient to avoid driving and other activities requiring alertness until 6 hr after each dose or until response to medication is known.
Advise patient to stop taking flibanserin and notify health care professional immediately if signs and symptoms of hypersensitivity reaction (swelling of the face, lips, and mouth; pruritus; urticaria) occur.
Instruct patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and consult health care professional before taking any new medications, especially St. John's wort.
Rep: Advise females of reproductive potential to notify health care professional if pregnancy is planned or suspected or if breastfeeding.

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇

Action ⬆ ⬇

Pharmacokinetics ⬆ ⬇