iloperidone (Fanapt)

Iloperidone is an oral, atypical antipsychotic used to treat schizophrenia. Other atypical antipsychotic drugs include

• olanzapine (Zyprexa),
• quetiapine (Seroquel),
• ziprasidone (Geodon), and
• aripiprazole (Abilify).

Atypical antipsychotics differ from typical antipsychotics because they cause a lesser degree of movement (extrapyramidal) side effects and constipation.

The exact mechanism of action of iloperidone is not known, but like other anti-psychotics, it is believed that iloperidone affects the way the brain works by interfering with communication among the brain's nerves. Nerves communicate with each other by making and releasing chemicals called neurotransmitters. The neurotransmitters travel to other nearby nerves where they attach to receptors on the nerves. The attachment of the neurotransmitters either stimulates or inhibits the function of the nearby nerves. iloperidone blocks several of the receptors on nerves including dopamine type 2, serotonin type 2, and alpha 2 adrenergic receptors. It is believed that many psychotic illnesses are caused by abnormal communication among nerves in the brain and that by altering communication through neurotransmitters, iloperidone can alter the psychotic state. Iloperidone was approved by the FDA in 2009.

What brand names are available for iloperidone?

Fanapt

Is iloperidone available as a generic drug?

No

Do I need a prescription for iloperidone?

Yes

The most common side effects include

• dizziness,
• dry mouth,
• fatigue,
• nasal congestion,
• orthostatic hypotension,
• somnolence,
• tachycardia, and
• weight gain.

Less common but serious side effects include:

• Increased risk of stroke in elderly patients with dementia-related psychosis.
• Neuroleptic malignant syndrome (NMS). NMS is a rare but serious side effects associated with the use of antipsychotics. NMS may result in death and must be treated in the hospital.
  • Signs and symptoms of NMS may include high fever, sweating (diaphoresis), severe muscle stiffness or rigidity, confusion, loss of consciousness, high blood pressure, rapid heartbeat, and changes in breathing.

Extrapyramidal side effects (EPS) including:

• Dystonia: painful spasms of the oral, throat, or neck muscles that may cause problems with speech, swallowing, and stiff neck.
• Akathisia: feelings of restlessness or difficulty sitting still.
• Pseudoparkinsonism: drug induced Parkinson's symptoms.
• Tardive dyskinesia (TD). TD usually occurs after long term use of antipsychotics and usually presents with movement problems affecting the tongue, lips, jaw, face, and extremities.
• Metabolic changes including high blood sugar (hyperglycemia), diabetes mellitus, increase in blood cholesterol, and weight gain.
• High blood levels of prolactin. Prolactin is a hormone that allows the production of breast milk. High levels of prolactin may cause menstrual abnormalities, leakage of milk from the breast, development of breasts in males, and erection problems in men.
• Seizures may occur.
• Iloperidone causes sedation and slows thinking and movement. Patients should avoid potentially dangerous activities such as driving and operating machinery until they are certain that iloperidone does not impair their ability to perform such tasks.

• The recommended target dose is 12 to 24 mg/day in two divided doses.
• TThe starting dose is 1 mg twice daily, then 2 mg on day 2, 4 mg on day 3, 6 mg on day 4, 8 mg on day 5, 10 mg on day 6, and 12 mg on day 7.
• Doses are given twice daily.
• Iloperidone may be administered without regard to meals.

Iloperidone can reduce blood pressure especially when standing up from a sitting or lying down position (orthostatic hypotension). Therefore, iloperidone should be used cautiously with other drugs also associated with orthostatic hypotension.

Iloperidone is broken down by enzymes in the liver. Drugs that block the action of these enzymes increase blood levels of iloperidone. Ketoconazole, fluoxetine (Prozac), and paroxetine (Paxil) increase blood levels of iloperidone through this mechanism.

The risk of abnormal heartbeats increases when iloperidone is combined with other drugs that cause abnormal heartbeats.

Currently there is no data on the use of iloperidone during pregnancy. Iloperidone should only be used during pregnancy if the potential benefit to the mother outweighs the potential for side effects in the fetus.

Fetuses exposed to antipsychotics during the third trimester of pregnancy are at risk for extrapyramidal and withdrawal symptoms after birth. Symptoms reported included agitation, hypertonia, hypotonia, tremor, somnolence, depressed breathing, and feeding disorder.

A pregnancy exposure registry has been established to monitor the use of atypical antipsychotics, including iloperidone, during pregnancy. All pregnant women treated with atypical antipsychotics are advised to enroll in this pregnancy registry and report any side effects.

Iloperidone has not been evaluated in nursing mothers.

What preparations of iloperidone are available?

How should I keep iloperidone stored?

Iloperidone should be stored at room temperature between 15 C and 30 C (59 F and 86 F).