Paliperidone, the active ingredient in INVEGA® (paliperidone) Extended-Release Tablets, is a psychotropic agent belonging to the chemical class of benzisoxazole derivatives. INVEGA® contains a racemic mixture of (+)- and (-)- paliperidone. The chemical name is (±)-3-[2-[4-(6-fluoro-1,2benzisoxazol-3-yl)-1-piperidinyl]ethyl]-6,7,8,9-tetrahydro-9-hydroxy-2-methyl-4Hpyrido[1,2-a]pyrimidin-4-one. Its molecular formula is C₂₃H₂₇FN₄O₃ and its molecular weight is 426.49. The structural formula is:

Paliperidone is sparingly soluble in 0.1N HCl and methylene chloride; practically insoluble in water, 0.1N NaOH, and hexane; and slightly soluble in N,N-dimethylformamide.

INVEGA® (paliperidone) Extended-Release Tablets are available in 1.5 mg (orange-brown), 3 mg (white), 6 mg (beige), and 9 mg (pink) strengths. INVEGA® (paliperidone) utilizes OROS® osmotic drug-release technology.

Inactive ingredients are carnauba wax, cellulose acetate, hydroxyethyl cellulose, propylene glycol, polyethylene glycol, polyethylene oxides, povidone, sodium chloride, stearic acid, butylated hydroxytoluene, hypromellose, titanium dioxide, and iron oxides. The 3 mg tablets also contain lactose monohydrate and triacetin.

Delivery System Components and Performance

INVEGA® uses osmotic pressure to deliver paliperidone at a controlled rate. The delivery system, which resembles a capsule-shaped tablet in appearance, consists of an osmotically active trilayer core surrounded by a subcoat and semipermeable membrane. The trilayer core is composed of two drug layers containing the drug and excipients, and a push layer containing osmotically active components. There are two precision laser-drilled orifices on the drug-layer dome of the tablet. Each tablet strength has a different colored water-dispersible overcoat and print markings. In an aqueous environment, such as the gastrointestinal tract, the water-dispersible color overcoat erodes quickly. Water then enters the tablet through the semipermeable membrane that controls the rate at which water enters the tablet core, which, in turn, determines the rate of drug delivery. The hydrophilic polymers of the core hydrate and swell, creating a gel containing paliperidone that is then pushed out through the tablet orifices. The biologically inert components of the tablet remain intact during gastrointestinal transit and are eliminated in the stool as a tablet shell, along with insoluble core components.

To reduce the risk of dizziness and lightheadedness, get up slowly when rising from a sitting or lying position. These side effects are more likely to occur in the first few days after starting/restarting the drug or after your dose increases.

An empty tablet shell may appear in your stool. This is harmless.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor immediately if any of these unlikely but serious side effects occur: difficulty swallowing, fast/slow/irregular heartbeat, restlessness, shaking (tremor), muscle spasms, pain/swelling/redness of arms or legs, signs of infection (such as fever, persistent sore throat).

Seek immediate medical attention if any of these rare but very serious side effects occur: seizures, fainting, weakness on one side of the body, slurred speech, chest pain, confusion, vision changes, trouble breathing.

Paliperidone may rarely cause a condition known as tardive dyskinesia. In some cases, this condition may be permanent. Tell your doctor immediately if you develop any unusual/uncontrolled movements (especially of the face, lips, mouth, tongue, arms, or legs).

This drug may infrequently cause a serious (rarely fatal) nervous system disorder (neuroleptic malignant syndrome). Seek immediate medical attention if you notice any of the following rare but very serious side effects: muscle stiffness/pain, high fever, increased sweating, mental/mood changes, change in the amount of urine.

Rarely, this medication may increase your blood level of a certain hormone (prolactin). In females, an increase in prolactin levels may result in unwanted breast milk, missed/stopped periods, or difficulty becoming pregnant. In males, it may result in decreased sexual ability, inability to produce sperm, or enlarged breasts. If you develop any of these symptoms, tell your doctor immediately.

For males, in the very unlikely event you have a painful or prolonged erection (lasting more than 4 hours), stop using this drug and seek immediate medical attention, or permanent problems could occur.

A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

PRECAUTIONS: Before taking paliperidone, tell your doctor or pharmacist if you are allergic to it; or to risperidone; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: severe liver disease, kidney disease, esophagus/stomach/intestinal movement or blockage disorders (e.g., difficulty swallowing, diarrhea, peritonitis, cystic fibrosis, Meckel's diverticulum), a severe loss of body water (dehydration), blood pressure problems, disease of the blood vessels in the brain (e.g., stroke), heart disease (e.g., ischemic heart disease), seizures, breast cancer, Parkinson's disease, Alzheimer's disease, low white blood cell count.

Also tell your doctor or pharmacist if you or a family member has a history of the following: alcohol/drug abuse, diabetes, obesity.

Paliperidone may cause a condition that affects the heart rhythm (QT prolongation). QT prolongation can infrequently result in serious (rarely fatal) fast/irregular heartbeat and other symptoms (such as severe dizziness, fainting) that require immediate medical attention. The risk of QT prolongation may be increased if you have certain medical conditions or are taking other drugs that may affect the heart rhythm (see also Drug Interactions section). Before using paliperidone, tell your doctor or pharmacist if you have any of the following conditions: certain heart problems (heart failure, slow heartbeat, QT prolongation in the EKG), family history of certain heart problems (QT prolongation in the EKG, sudden cardiac death).

Low levels of potassium or magnesium in the blood may also increase your risk of QT prolongation. This risk may increase if you use certain drugs (such as diuretics/"water pills") or if you have conditions such as severe sweating, diarrhea, or vomiting. Talk to your doctor about using paliperidone safely.

This drug may make you dizzy or drowsy. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely. Avoid alcoholic beverages.

This drug may infrequently make your blood sugar level rise, causing or worsening diabetes. This high blood sugar can rarely cause serious conditions such as diabetic coma. Tell your doctor immediately if you develop symptoms of high blood sugar such as unusual increased thirst/urination or vision changes. If you already have diabetes, be sure to check your blood sugar level regularly.

This drug can make you more likely to get heat stroke. Avoid activities that may cause you to overheat (e.g., strenuous work, exercising in hot weather, using hot tubs). Drink plenty of fluids, dress lightly, and stay in cool/air-conditioned areas when the weather is hot.

Kidney function declines as you grow older. This medication is removed by the kidneys. Therefore, elderly people may be at greater risk for side effects while using this drug.

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor. Do not stop taking this medication unless directed by your doctor. Babies born to mothers who have used this drug during the last 3 months of pregnancy may infrequently develop symptoms including muscle stiffness or shakiness, drowsiness, feeding/breathing difficulties, or constant crying. If you notice any of these symptoms in your newborn anytime during their first month, tell the doctor right away.

This medication passes into breast milk and may have undesirable effects on a nursing infant. Consult your doctor before breast-feeding.