Invega (Paliperidone) Dosage and Side Effects
INVEGA is a prescription medicine used to treat the symptoms of schizophrenia and related psychotic disorders.
Warnings and Precautions
Studies with various medicines of the group to which INVEGA belongs, have been associated with an increased rate of death when used in elderly patients with dementia. Some of these studies included treatment with a related drug, RISPERDAL (risperidone). INVEGA is not indicated in elderly patients with dementia.
BEFORE you use INVEGA, talk to your doctor or pharmacist if you:
- have had serious allergic reactions to other medications, including risperidone
- have a history of stroke, mini-stroke, high cholesterol or high blood pressure
- were previously diagnosed with a condition known as Neuroleptic Malignant Syndrome (high temperature and muscle stiffness) or Tardive Dyskinesia (abnormal movements of the tongue or face). Both of these are conditions caused by antipsychotic drugs
- have diabetes or are at a risk for diabetes or a family history of diabetes
- are pregnant or planning to become pregnant
- are breast-feeding or planning to breast feed
- have a history of problems with the heart and/or blood vessels
- have/had a heart disease or heart disease treatment that makes you prone to low blood pressure or feeling dizzy or faint when you stand up from lying or sitting positions
- have/have ever had blackouts or seizures
- have or have had low white blood cell counts in your blood. Let your doctor know right away if you develop a fever or infection while being treated with INVEGA.
- have risk factors for developing blood clots such as: a family history of blood clots, age over 65, smoking, obesity, recent major surgery (such as hip or knee replacement), immobility due to air travel or other reasons, or take oral contraceptives (“The Pill”).
- have a narrowing or blockage of your gastrointestinal tract (your esophagus, stomach, or large or small intestine)
- have diseases associated with diarrhea
- have Parkinson’s disease or Dementia with Lewy Bodies (DLB)
- are taking or planning to take any other medicines (prescription or over-the-counter)
- drink alcoholic beverages or use drugs
- suffer from lactose intolerance because INVEGA tablets contain lactose
- are taking RISPERDAL (risperidone)
- have a history of kidney problems
- have liver problems
- suffer from Alzheimer’s disease
- are dehydrated
- exercise strenuously
- have or have had breast cancer
- have pituitary tumours
- are planning to have an operation on the eye
- are feeling thirsty and unwell
Like other medications, INVEGA can cause some side effects. These side effects are most likely to be minor and temporary. However, some may be serious and need medical attention. Many of the side effects are dose related, so it is important not to exceed your prescribed dose. Should you experience these symptoms, please consult your doctor.
Very commonly headache, or feeling sleepy or less alert may be experienced.
Common side effects may include: common cold symptoms, sinus infection, difficulty falling or staying asleep, mania, irritability, depression, anxiety, faster heart rate, slowed heart rate, heartbeat irregularities, lack of energy, restlessness, feeling dizzy, stuffy nose, drop in blood pressure upon standing, high blood pressure, stomach ache, dry mouth, itching, increased saliva, being sick (vomiting), diarrhea, uncontrollable movements of the face, eyes or body, trembling, slowness of movement, muscle stiffness or spasm, and increased appetite.
Weight gain has been reported with INVEGA. Your doctor should check your body weight before starting INVEGA and continue to monitor it for as long as you are being treated.
Uncommon side effects may include: urinary tract infection, feeling like you have the flu, weight loss, anemia, high blood triglycerides (a fat), nightmares, swelling of legs or other body area, increased liver transaminases in your blood, rash, a restless urge to move parts of your body, fainting, sensation the room is spinning, sensation your heart is racing, variation in heart rate, heart rhythm changes, decreased blood pressure, decreased blood flow, rigid muscles, muscle weakness, and joint swelling.
INVEGA can raise your levels of a hormone called “prolactin” (measured with a blood test). Women may experience leakage of fluid or milk from the breast even if they are not pregnant, breast discomfort, or missed or irregular periods, or other problems with your cycle. Men may experience breast swelling/enlargement or difficulty getting or maintaining an erection or other sexual dysfunction.
High blood sugar has been reported. See your doctor if you experience symptoms such as excessive thirst or urination.
Your doctor should take blood tests before starting INVEGA. They will monitor blood sugar, and the number of infection-fighting white blood cells. Your doctor should continue to monitor your blood for as long as you are being treated.
If you have high levels of prolactin (measured with a blood test) and a condition called hypogonadism you may be at an increased risk of breaking a bone due to osteoporosis. This occurs in both men and women.
In rare cases, the following may happen: low blood sugar, diabetes mellitus or worsening of diabetes, increased cholesterol, loss of consciousness, heartbeat irregularities, joint stiffness, and vaginal discharge.
Lack of bowel muscle movement that causes blockage may occur very rarely.
Side effects where the frequency is not known include glaucoma (increased pressure within the eyeball), and problems with the movement of your eyes.
During cataract surgery, a condition called intraoperative floppy iris syndrome (IFIS) can happen if you take or have taken INVEGA. If you need to have cataract surgery, be sure to tell your eye doctor if you take or have taken INVEGA.
Since paliperidone is a compound resulting from the breakdown of risperidone in the human body, any side effects that may occur after taking risperidone may also occur with INVEGA.
If you notice any side effects not listed in this leaflet, please tell your doctor or pharmacist.
Do not be alarmed by this list of possible side effects. You may not experience any of them. If any of these side effects are experienced, they are usually mild and temporary. However, do not hesitate to report undesired side effects to your doctor.
If you have taken INVEGA in the last three months of your pregnancy and you notice that your newborn baby develops shaking, muscle stiffness and/or weakness, sleepiness, agitation, breathing problems or difficulty in feeding, seek immediate emergency medical attention.
Interactions with this medication
Inform all doctors, dentists and pharmacists who are treating you that you are taking INVEGA. Inform them if you are taking or are planning on taking any other medicine, including prescription, over-the-counter, or natural health products. They will tell you which medicines you can take with INVEGA.
Since INVEGA works primarily in the brain, interference with other drugs that work in the brain (including alcohol) could occur. It is recommended that you DO NOT drink alcohol and only take drugs prescribed by your doctor.
Inform your doctor if you start or stop taking any of the following medications:
- Valproate (drugs used to treat seizures, manic-depression and migraines)
- INVEGA should be used with caution when taking medications that may change the electrical activity of the heart, such as but not restricted to: medicines for malaria, heart rhythm disorders, allergies, other antipsychotics, antidepressants, water tablets or other medicines affecting body salts (sodium, potassium, magnesium)
- Phenothiazines and some heart medications (e.g., medication for high blood pressure, antiarrhythmics, or beta-blockers), as these may interact with INVEGA to cause your blood pressure to drop too low
- Dopamine agonists, e.g. levodopa (antiparkinsonian agent), may decrease the effect of INVEGA
- Carbamazepine (an anticonvulsant) has been shown to decrease the levels of INVEGA in your blood.
Proper Use of this medication
Do not chew, crush or divide the tablets. Swallow INVEGA tablets whole with water or other liquids.
Take INVEGA once each day preferably in the morning with or without food.
The INVEGA tablet does not dissolve completely after all the drug has been released, and you may sometimes notice it in your stool. This is normal.
It is very important that you take—give INVEGA the way the doctor has prescribed it.
The doctor has decided on the best dosage for you—the patient you are caring for based on individual needs. Dosage may be increased or decreased depending on the response.
It is important that you keep taking—giving INVEGA even after your/the symptoms have improved or disappeared. Do not change or stop taking—giving INVEGA without consulting the doctor.
DO NOT give INVEGA to anyone else. The doctor has prescribed it for you—the patient you are caring for.
Usual adult dose:
The usual starting dose is 6 mg once daily.
In case of drug overdose, contact a health care practitioner, hospital emergency department or regional Poison Control Centre immediately, even if there are no symptoms.
One or more of the following signs may occur in an overdose: sleepiness, drowsiness, tiredness, abnormal body movements, problems with standing and walking, dizziness from low blood pressure, abnormal heartbeats, rapid heartbeat, reduced consciousness, and excessive trembling or excessive muscle stiffness.
If you miss a dose, do not take a double dose to make up for a forgotten dose.
If you miss one dose, take your next dose on the day following the missed dose.
If you miss two or more doses, contact your doctor.