DrugindexOnline^{2nd edition}

Pronouncation: (PAL-ee-PER-i-done)
Class: Benzisoxazole derivative

Trade Names:
Invega
- Tablets, extended-release 3 mg
- Tablets, extended-release 6 mg
- Tablets, extended-release 9 mg

Mechanism of Action

Pharmacology

Antipsychotic effects, possibly due to dopamine and serotonin receptor blockade in the CNS.

Pharmacokinetics

Absorption

Dose-related pharmacokinetics. Bioavailability is approximately 28%. C _max occurs approximately 24 h after dosing. Steady-state concentrations are reached within 4 to 5 days. Mean steady-state peak-to-trough ratio ranges from 1.2 to 3.1.

Distribution

Vd is 487 L. Plasma protein binding is 74%.

Metabolism

Limited degree of metabolism by CYP2D6 and CYP3A4.

Elimination

Elimination t _½ is approximately 23 h. Elimination is approximately 80% in urine and 11% in feces; 32% recovered as metabolites.

Special Populations

Renal Function Impairment

Reduce dose in patients with moderate or severe impairment.

Hepatic Function Impairment

No adjustments needed in mild or moderate impairment. Effect of severe impairment has not been determined.

Indications and Usage

Acute and maintenance treatment of schizophrenia.

Contraindications

Hypersensitivity to risperidone, paliperidone, or any component of the product.

Dosage and Administration

Adults

PO 6 mg once daily in the morning. Some patients may benefit from doses of 3 to 12 mg/day. Dose increases above 6 mg/day should be made only after reassessment and at increments of 3 mg/day at intervals of at least 5 days (max, 12 mg/day).

Renal Function Impairment

For mild impairment (CrCl 50 to less than 80 mL/min), do not exceed 6 mg once daily. For moderate to severe impairment (CrCl 10 to less than 50 mL/min), do not exceed 3 mg once daily.

General Advice

• May be taken with or without food.
• Tablets must be swallowed whole and not divided, chewed, or crushed.

Storage/Stability

Store at 59° to 86°F. Protect from moisture.

Drug Interactions

Alcohol, CNS-acting drugs

Use with caution.

Drugs that cause orthostatic hypotension

Possible additive effect with paliperidone.

Drugs that prolong the QTc interval (eg, antibiotics [gatifloxacin, moxifloxacin], antipsychotic agents [eg, chlorpromazine, thioridazine], class IA antiarrhythmic agents [eg, procainamide, quinidine], class III antiarrhythmic agents [eg, amiodarone, sotalol])

Avoid coadministration of paliperidone with these agents.

Levodopa and other dopamine agonists

Effects may be antagonized by paliperidone.

Laboratory Test Interactions

None well documented.

Adverse Reactions

Cardiovascular

Tachycardia (14%); orthostatic hypotension, prolonged QTc interval (5%); bundle branch block (3%); abnormal ECG T wave, first-degree AV block, increased blood pressure, sinus arrhythmia (2%); palpitations (at least 1%).

CNS

Headache (14%); somnolence (11%); akathisia, hyperkinesia (10%); anxiety, dyskinesia (9%); extrapyramidal disorder (7%); dizziness (6%); dystonia (5%); hypertonia, tremor (4%); asthenia, fatigue, parkinsonism, pyrexia (2%).

EENT

Blurred vision (2%).

GI

Nausea (6%); dyspepsia (5%); salivary hypersecretion (4%); dry mouth, upper abdominal pain (3%); abdominal pain (at least 1%).

Lab Tests

Increased blood insulin (2%).

Musculoskeletal

Back pain, extremity pain (2%).

Respiratory

Cough (3%); dyspnea (at least 1%).

Precautions

Warnings There is an increased risk of mortality in elderly patients with dementia-related psychosis.

Pregnancy

Category C .

Lactation

Excreted in breast milk.

Children

Safety and efficacy not established.

Antiemetic effect

Because paliperidone may have an antiemetic effect, signs and symptoms of overdosage with certain drugs or conditions (eg, brain tumor, intestinal obstruction) may be masked.

Body temperature regulation

Antipsychotics disrupt the ability to reduce core body temperature. Use with caution in patients who will experience conditions that may contribute to an elevation in core body temperature (eg, concomitant anticholinergic therapy, exposure to extreme heat, strenuous exercise, subject to dehydration).

Cerebrovascular events

Cerebrovascular adverse reactions (eg, stroke, transient ischemic attack), including fatalities, may occur.

CV

Because QTc prolongation may occur, avoid use in patients receiving other drugs that prolong the QTc interval and in patients with congenital long syndrome or history of cardiac arrhythmias.

Dysphagia

Use with caution in patients at risk of aspiration pneumonia.

GI

Because tablet does not change shape in the GI tract, paliperidone is usually not administered to patients with preexisting severe GI narrowing (eg, cystic fibrosis).

Hyperglycemia

Hyperglycemia, in some cases extreme and associated with ketoacidosis or hyperosmolar coma or death, may occur.

Hyperprolactinemia

Prolactin levels may be elevated.

Neuroleptic malignant syndrome

Has occurred and is potentially fatal. Signs and symptoms include altered mental status, diaphoresis, hyperpyrexia, irregular BP, irregular pulse, muscle rigidity, and tachycardia.

Orthostatic hypotension

Orthostatic hypotension associated with bradycardia, dizziness, syncope, and tachycardia may occur.

Priapism

May occur; severe priapism may require surgical intervention.

Seizures

May occur; use with caution in patients with a history of seizures.

Special risk patients

Patients with Parkinson disease or dementia with Lewy bodies may have increased sensitivity to paliperidone, which may manifest as confusion, obtundation, extrapyramidal symptoms, or neuroleptic malignant syndrome.

Suicide

Supervise depressed patients at risk during initial therapy. Prescribe lowest quantity consistent with good patient management in order to reduce risk of overdose.

Tardive dyskinesia

Syndrome of potentially irreversible, involuntary dyskinetic movements may develop. Prevalence is higher in elderly patients, especially women. Use lowest effective dose for shortest period of time needed.

Overdosage

Symptoms

Drowsiness, extrapyramidal symptoms, hypotension, QT prolongation, sedation, tachycardia, unsteady gait.

Patient Information

• Advise patient that drug may cause drowsiness or impaired judgment or thinking skills, and to use caution while driving, riding a bike, or performing other tasks requiring mental alertness until tolerance is determined.
• Advise patient to get up slowly from a lying or sitting position and to avoid sudden position changes to prevent postural hypotension.
• Advise patient to avoid alcohol while taking paliperidone.
• Advise patient to avoid strenuous activity during periods of high temperature or humidity and to avoid overheating and dehydration.
• Advise patient to swallow tablet whole; tablet should not be divided, chewed, or crushed.