Schizophrenia is a mental health disorder that causes changes to the way a person thinks, acts, and behaves. People with schizophrenia may have hallucinations, delusions, disorganized behavior, and trouble thinking clearly.
Invega tablets were approved in 2006 for schizophrenia. Since then, a once-monthly injection, an every three-month injection, and an every six-month injection have also been approved. Invega is an atypical antipsychotic that contains the active ingredient paliperidone. It does not cure the disorder but helps to control symptoms.
Studies show that Invega can improve symptoms of schizophrenia and reduce the risk of relapse with as little as two doses a year.
How Does It Work?
People with schizophrenia have an imbalance of chemicals in the brain. Invega helps to balance serotonin and dopamine levels in the brain, which decreases the symptoms of schizophrenia.
How Do I Take It?
Invega is available as an oral tablet or as an intramuscular injection.
The oral tablet is taken by mouth once a day. It can be taken with or without food. It should be swallowed whole with a glass of water. You should not crush, divide, or chew the tablet. The tablet contains an outer shell that does not fully break down in the body. Don’t be alarmed if you see this in your stool.
Invega injections will be given by a health care provider in a medical office, clinic, or hospital. After initial treatments, maintenance doses are available in three different dosage forms.
- Invega Sustenna, given once a month
- Invega Trinza, given every three months
- Invega Hafyera, given every six months
How Was It Studied for the Treatment of Schizophrenia?
Invega tablets
Three studies evaluated the effectiveness and safety of Invega in adults with schizophrenia. The average age of people in these studies ranged from 36 to 39. Sixty-two percent of people in these studies were male.
In these studies, people received either Invega, a placebo, or olanzapine. Olanzapine is another effective treatment option for schizophrenia and was used as a comparison. People who received Invega received varying strengths from 3 milligrams to 15 milligrams. After 6 weeks, they could participate in the maintenance phase where everyone received Invega.
Results showed that all doses of Invega were more effective than a placebo. Some people showed improvement in symptoms within four days of starting Invega. These studies showed that Invega can improve symptoms and maintain control with long-term treatment.
Sustenna injection
The effectiveness and safety of Invega Sustenna was determined by a clinical study. People in these studies were over the age of 18, with an average age of 39. The majority of people in these studies were male, at 67%.
The study included an initial phase where Invega Sustenna was administered on day 1 and day 8. People then received either Invega Sustenna or a placebo once a month for 6 months. They could then go on to receive Invega Sustenna for an additional year.
For all injection studies, the effectiveness was based on whether the people experienced a relapse while on the medicine. The criteria that measured relapses included:
- Psychiatric hospitalization due to symptoms
- Self-injury
- Aggressive or suicidal behavior
- Significant changes in the Positive and Negative Syndrome Scale for Schizophrenia (PANSS)
Results showed that once-monthly Invega Sustenna is effective at reducing symptom severity. People taking Sustenna showed an improvement in PANSS scores compared to those taking the placebo. Improvements were seen as early as day 8 with Invega Sustenna. Those taking the placebo had a four times higher risk of relapse compared to those taking Invega Sustenna.
Trinza injection
A clinical study evaluated the time to relapse when taking Invega Trizna, which is given every three months, compared to a placebo. People in this study were between the ages of 18 to 70, with an average age of 38. Seventy-five percent of the people in this study were male. Sixty-four percent were White, 15% were Black, 10% were Asian, and 11% were other races.
All people in this study received initial Invega Sustenna doses for three months. They then received one dose of Invega Trinza. Three months later they received either Invega Trinza or a placebo.
Results showed that people treated with Invega Trinza had a longer time to relapse than those who received a placebo. Of those taking placebo, 23% had a relapse, while about 7% of people who continued on Invega Trinza had a relapse. For people who took the placebo, the median time it took to relapse was 274 days.
Hafyera injection
A clinical study evaluated the effectiveness of Invega Hafyera, which is given every six months, with Invega Trinza, which is given every three months. People in this study were between the ages of 18 to 69, with an average age of 41. Sixty-eight percent of people in this study were male.
All people in this study were given initial Invega Sustenna doses and were then transitioned to either Invega Trinza or Invega Hafyera.
About 93% of people taking Invega Hafyera and 95% of people taking Invega Trinza did not have a relapse. This proved that Invega Hafyera has comparable efficacy to Invega Trinza. Long-term studies show that Invega Hafyera is an effective treatment option with only two doses a year.
How Long Does It Take to Work?
Some people in the studies noticed improvement within the first week of starting Invega. For others, it may take several weeks to see an effect. Most people need several months of treatment for the full benefits. Talk with your health care provider if you don’t notice an improvement within several weeks.
How Can I Prevent and Manage Side Effects?
The most common side effects from studies are involuntary movements, drowsiness, headache, and weight gain. The injectable forms can also cause reactions where the needle entered the skin.
Atypical antipsychotics like Invega commonly cause extrapyramidal symptoms (EPS). EPS is a group of side effects that cause a range of movement disorders, specifically involuntary muscle movements. You may feel restless and have the need to constantly move or fidget. You may also develop a tremor, have difficulty speaking, or have painful muscle contractions. With long-term use, tardive dyskinesia can develop and may be permanent. Your face may move involuntarily, such as blinking a lot or sticking out your tongue. If you develop EPS, talk with your health care provider. They may lower your dose, change your medication, or recommend a medication to help decrease symptoms.
Drowsiness can occur with Invega. Avoid driving or other tasks that require alertness until you know how Invega affects you.
Invega can also cause low blood pressure upon standing. This can cause dizziness and fainting. This can happen when going from sitting to standing or lying down to standing. Make sure you stand up slowly and use support if needed. If you feel dizzy or faint, sit or lie back down. Also, make sure you are drinking enough water.
Headaches can happen when using Invega. Talk with your health care provider or pharmacist for tips on how to manage them, including advice on OTC pain relievers that might help.
Invega can cause increases in blood sugar levels, cholesterol levels, blood pressure, and weight. Your provider will regularly monitor your weight, blood pressure, cholesterol, and blood sugar levels. It is important to eat a healthy diet and exercise regularly. Limiting foods high in fat, sugar, and salt can lower your risk of these side effects.
Invega causes an increased risk of stroke in older adults with dementia-related psychosis. Invega is not approved to treat dementia-related psychosis.
Invega injections can cause reactions in your skin where the needle went in (called injection site reactions). The reactions are usually mild and include itching, redness, swelling, and warmth. Applying a cool compress to the area may help. Your health care provider or pharmacist may recommend an over-the-counter (OTC) pain reliever, such as acetaminophen, or an OTC antihistamine for itching.
These are not all of the possible side effects of Invega. Talk with your health care provider if you are having symptoms that bother you. You can also report side effects to the FDA at 800-FDA-1088 (800-332-1088). In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.
What Type of Drug Interactions Can Happen?
Invega can cause orthostatic hypotension (low blood pressure upon standing), so you should avoid other medications that increase this risk. Tell your health care provider about all medicines you take including blood pressure medications like lisinopril.
Invega causes drowsiness, so you should avoid other medications that make you tired. Tell your health care provider about all medicines you take including central nervous system (CNS) depressants, like alprazolam and alcohol. Your pharmacist can tell you if any of the medicines you take are CNS depressants.
Several medicines are called inducers of both P-gp and an enzyme called CYP3A4. These medicines may make Invega not work very well. Ideally, you will not take both Invega and a P-gp/3A4 inducer. Ask your health care provider if any of your medicines may cause this interaction. If you do, tell your health care provider if you feel that Invega is not working.
Divalproex sodium can increase the effect of Invega and can increase the risk of side effects. Your health care provider may have to adjust your Invega dose if you take divalproex sodium.
Invega can cause changes in your heart rhythm, so you should avoid other medications that increase this risk. Tell your health care provider if you take an anti-arrhythmia medicine such as dofetilide.
Invega can decrease the effect of some medicines used for Parkinson’s disease, like levodopa. Your health care provider will monitor your treatment and will make changes if necessary.
Tell your health care provider and pharmacist about all prescription drugs, over-the-counter (OTC) medications, vitamins/minerals, herbal products, and supplements you take or have recently taken. This will help determine if there are any interactions with Invega.
What Do I Need to Do to Get It?
Invega requires a prescription from a health care provider. The tablet form and generic options are available at retail and mail-order pharmacies.
The injectable forms of Invega are a specialty medicine and may require a prior authorization from your insurance. Your health care provider will work with your insurance to get it covered for you. The injectable forms will be given by a health care provider at a medical office or clinic.
Is There Any Cost Assistance Available?
A savings program is available from the drugmaker. You may pay as little as $10 for each injection. This does not include the injection fee. Eligibility depends on your current prescription insurance coverage. For more information, call 855-452-6773 or visit Janssencarepath.com.
For any other questions about Invega, you can contact the drugmaker at 800-526-7736.
