It can help you think more clearly, feel less agitated, and behave more productively. For many people, Invega may have fewer side effects than other antipsychotic drugs. It may be taken via a long-acting injection which can help with adherence and may allow you to not have to take a daily pill.
How Invega Works
Invega works by restoring the balance of certain neurotransmitters in the brain. Invega impacts dopamine and serotonin in the brain. It works similarly and is chemically related to Risperdal, but often with fewer extrapyramidal side effects (such as tremor or stiffness). Serotonin is thought to regulate anxiety and mood, among several other functions. Dopamine is central to such central nervous system functions as movement, pleasure, attention, mood, and motivation. By balancing these neurotransmitters in the brain, Invega can help alleviate some of the symptoms of schizophrenia, including:
Delusions (false beliefs)Hallucinations (false sensory experiences)Disorganized thinking and speechDisorganized and unpredictable behavior
What to Expect
It may take several weeks for Invega to take full effect so it may be a while before you know if it’s the right medication for you. Hallucinations, delusions, and disorganized thinking may improve in the first 1 to 2 weeks. These symptoms may not completely go away. However, symptoms often become better the longer you take Invega.
Invega Dosage
Invega tablets are usually taken once per day or as directed by your doctor. The dose usually ranges from 3 mg to 12 mg. Typically, you’ll be prescribed a low dose to start and then the dose may slowly be increased over several weeks. Tablets should be swallowed whole (they should not be crushed, broken, or chewed). Patients who tolerate the pill form well may be able to take long-acting injections. This can be especially helpful if you tend to forget your medication, don’t want to be on pills, or if adherence is a problem.
Types of Invega
There are different types of Invega that you may be prescribed, with different dosage and timing.
Invega Sustenna
Invega Sustenna is an intramuscular injection given every month. It needs to be given by a healthcare professional. It’s usually injected into the upper arm or buttocks. The first two doses are usually given one week apart. After the first two doses, the medication is usually given once a month (or as directed by your doctor). The medication is gradually released over time to help control symptoms.
Invega Trinza
Invega Trinza is an injection that lasts three months, meaning that patients only need to take four doses per year. Like Invega Sustenna, it is administered by a healthcare professional in the upper arm or buttocks. It may be administered once patients have been adequately treated with Invega Sustenna a for at least four months.
Invega Effectiveness
When used to treat schizophrenia, studies have consistently shown that Invega is both effective and well-tolerated, whether in pill form or as an injection. For schizoaffective disorder, Invega has proven equally effective as a maintenance therapy, preventing the reappearance of symptoms. By contrast, there have been few studies evaluating the effectiveness of Invega in treating acute bipolar mania. Of those that have been performed, results have been largely mixed. A 2012 review of studies from Nova Southeastern University in Florida concluded that Invega may be safe and useful in treating acute episodes of mania in bipolar disorder at higher doses. By contrast, a 2018 meta-analysis from China reported that Invega performed no better than a placebo in people with bipolar mania and caused far more side effects.
Common Side Effects of Invega
The most common side effects associated with Invega use include:
RestlessnessDizziness (vertigo)HeadachesFatigueBalance problemsMuscle weaknessIncreased saliva productionStomach painWeight gainConstipationHeartburnIncrease in the hormone prolactin
Invega SUSTENNA and Invega TRINZA were associated with the additional side effects of injection site redness, swelling, or pain. Talk to your doctor if the side effects are persistent or severe, and ask questions before you start treatment so that you’re better prepared if side effects do arise.
Serious Side Effects of Invega
Some side effects of Invega can be serious. In rare cases, a person may be allergic to Invega and develop a potentially deadly, all-body reaction known as anaphylaxis. Call 911 or go to the nearest emergency room if you develop any of the following: There was an error. Please try again.
Rash or hivesShortness of breath and/or wheezingDifficulty swallowing (dysphagia)Swelling in the face, throat, neck, or extremitiesHigh fever (over 100.4 F)Neuroleptic malignant syndrome (which is rare with this medication)
Serious side effects of Invega Sustenna and Invega Trinza are also uncommon but may include:
Seizures, tics, tremors, or convulsionsMuscle rigidityIrregular heartbeat (arrhythmia)A painful erection that can last for hours (priapism)
Long-Term Side Effects of Invega
Tardive dyskinesia is a side effect that develops with long-term use of antipsychotics. Symptoms include grimacing, sucking, smacking of lips, and other involuntary movements. While the risk of tardive dyskinesia is lower in Invega as compared to many other antipsychotics, the risk still exists.
Invega Drug Interactions
Tell your doctor about any or all medication you may be taking, whether they be over-the-counter, prescription, nutritional, herbal, or homeopathic. Some may interact with Invega, including:
Anti-arrhythmic (irregular heartbeat) drugsAnticonvulsant (anti-seizure) drugsAntidepressantsAntihypertensive (high blood pressure) drugsAnxiolytic (anti-anxiety) drugsCertain antibiotics, such as Avelox (moxifloxacin) or Erythrocin (erythromycin)Sedatives and sleeping pillsSt. John’s Wort
Invega may block the effects of drugs used to treat Parkinson’s disease, such as bromocriptine, pramipexole, ropinirole, levodopa, and others. Invega may also lower blood pressure. Medications used to lower blood pressure may increase this effect and increase your risk of falls. Carbamazepine (Tegretol, Equatro) may decrease the effects of Invega. Invega can make you drowsy so it’s important to be cautious about driving or operating heavy machinery. Alcohol can amplify these effects and should be avoided.
Contraindications
Invega carries the same black box warning as other atypical antipsychotics regarding the increased risk of death in elderly people with dementia-related psychosis. Invega, either in pill or injectable form, is not approved for use in this population. Invega is also contraindicated for patients with a known sensitivity to risperidone or Risperdal Consta.
Precautions and Considerations
Invega may contribute to weight gain and increase in blood sugars and lipids. It is important to have your blood sugar monitored while undergoing Invega treatment. If you are pregnant, planning to become pregnant, or are breastfeeding, tell your doctor immediately. Although there are no known risks based on animal studies, human data around potential risks is limited. Therefore, it is important to discuss the pros and cons of treatment with your doctor to make an informed choice.
