Paliperidone

Paliperidone is a prescription drug used for the treatment of schizophrenia.

Paliperidone belongs to a family of drugs called atypical antipsychotics. Other members of this family include risperidone (Risperdal) and ziprasidone (Geodon).

Paliperidone was approved by the Food and Drug Administration (FDA) in 2006, and is marketed as Invega by Ortho-McNeil-Janssen, in the United States.

Uses

Paliperidone is used for the the treatment of schizophrenia (a mental illness that causes disturbed or unusual thinking, loss of interest in life, and strong or inappropriate emotions).

Paliperidone does not cure schizophrenia. It is used to treat worsening symptoms of the disease and, in some, to control symptoms over an extended period of time.

How Paliperidone is Taken

Paliperidone is available as an extended-release (long-acting) tablet that is taken by mouth. It comes in the following strengths and colors:

• 3 mg (white)
• 6 mg (beige)
• 9 mg (pink)

The recommended dose of paliperidone is 6 mg taken once daily, administered in the morning, with or without food.

Some patients may benefit from higher doses, up to a maximum of 12 mg each day. For other patients, a lower dose of 3 mg per day may be sufficient to control the symptoms of schizophrenia.

How Paliperidone Works

The exact mechanism of atypical antipsychotics like paliperidone is not understood.

Paliperidone's action in schizophrenia, however, is believed to involve binding to dopamine Type 2 and serotonin Type 2 receptors in the brain.

How the Body Affects Paliperidone

Fifty-nine percent of a dose taken by mouth is excreted unchanged into the urine, 32% of the dose is excreted as metabolites both in the urine and feces, and 6% to 12% of the original dose is not excreted at all.

Side Effects

The most common side effects (reported in more than 5% of subjects treated with paliperidone and at least twice the rate seen in those taking placebo) were akathisia ("inner restlessness") and extrapyramidal disorders (changes in muscle tone and movements).

Other side effects may occur including the following:

• dizziness
• extreme tiredness
• weakness
• headache
• dry mouth
• increased saliva
• weight gain
• stomach pain
• fever
• muscle pain or stiffness
• confusion
• fast, pounding, or irregular heartbeat
• sweating
• unusual movements of the face or body that cannot be controlled
• painful erection of the penis that lasts for hours

Risks and Precautions

Studies have shown that older adults with dementia (a brain disorder that affects the ability to remember, think clearly, communicate, and perform daily activities and may cause changes in mood and personality) who take antipsychotics (medications for mental illness) such as paliperidone have an increased risk of death during treatment. Older adults with dementia may also have a greater chance of having a stroke or ministroke during treatment.

Neuroleptic malignant syndrome has been reported in treated with antipsychotic medications, including paliperidone. This syndrome is potentially fatal.

Tardive dyskinesia can also occur in people taking antipsychotic drugs. The risk of developing this complication is higher in the elderly, particularly elderly women. The syndrome results in potentially irreversible, involuntary, abnormal movements of the eyes, mouth, arms, and legs.

Paliperidone may cause patients to become more sensitive to extreme temperatures such as very hot or cold environments. Avoid getting too cold, or becoming overheated or dehydrated.

Paliperidone use may impair thinking or reaction time. Paliperidone may also induce sleepiness. So, it is advisable not to drive or operate heavy machinery while taking this drug.

Drug Interactions

Paliperidone should not be used in people taking medications that can cause an abnormality in conduction of electrical impulses in the heart. Drugs that do this are said to cause a prolonged QTc interval on an ECG and include quinidine, procainamide, amiodarone, sotalol, chlorpromazine, thioridazine, gatifloxacin, and moxifloxacin.

Paliperidone should be used with caution in combination with drugs that act on the central nervous system including alcohol.

Paliperidone may worsen the effect of levodopa and other dopamine agonists medications (used for Parkinson disease).

Because of its potential for causing orthostatic hypotension (a drop in blood pressure when standing up from a lying position), a worsening effect may be observed when paliperidone is administered with other drugs that cause orthostatic hypotension.

Effectiveness

One study of 628 patients with acute schizophrenia demonstrated that both 6 mg, 9 mg, and 12 mg daily doses of paliperidone improved symptoms of schizophrenia compared to placebo.^[1]

In another study, paliperidone 6 mg, but not 12 mg, was associated with significant improvements in personal and social performance in 444 patients with schizophrenia compared to placebo.^[2]

References

1. ↑ Kane J, Canas F, Kramer M, et al. Treatment of schizophrenia with paliperidone extended-release tablets: a 6-week placebo-controlled trial. Schizophr Res. 2007 Feb;90(1-3):147-61. Abstract
2. ↑ Marder SR, Kramer M, Ford L, et al. Efficacy and safety of paliperidone extended-release tablets: results of a 6-week, randomized, placebo-controlled study. Biol Psychiatry. 2007 Dec 15;62(12):1363-70. Abstract

External Links

Ortho-McNeil-Janssen: Invega

CenterWatch: Newly Approved Drugs: Paliperidone

Food and Drug Administration (FDA): Paliperidone Patient Information Sheet

Medline Plus: Paliperidone