Introduction
Living with schizophrenia or schizoaffective disorder can be difficult. Many people struggle with symptoms returning because they forget daily medication or stop treatment too early. A long-acting treatment option can help improve medication adherence and symptom control. Invega Sustenna is a once-monthly injection designed to provide continuous treatment and help patients maintain stability under the supervision of a healthcare provider.
What Is Invega Sustenna?
Invega Sustenna is a prescription medication containing paliperidone palmitate, an atypical antipsychotic. It is a long-acting injectable medicine that slowly releases medication into the body over time.
Unlike daily tablets, this injection is given by a healthcare professional and usually requires only one dose every month after the initial treatment period.
Drug Facts
- Generic name: Paliperidone palmitate
- Brand name: Invega Sustenna
- Drug class: Atypical antipsychotic
- Administration: Intramuscular injection
- Availability: Prescription only
- Generic version: Not currently available
What Is Invega Sustenna Used For?
Doctors prescribe Invega Sustenna for:
Schizophrenia
Schizophrenia is a chronic mental health condition that may cause:
- Hallucinations
- Delusions
- Confused thinking
- Social withdrawal
- Emotional changes
Monthly injections help maintain consistent medication levels and reduce relapse risk.
Schizoaffective Disorder
The medicine is also approved for adults with schizoaffective disorder. It may be used:
- Alone
- Together with antidepressants
- Alongside mood stabilizers
How Does Invega Sustenna Work?
The active ingredient, paliperidone, affects dopamine and serotonin receptors in the brain.
These chemical messengers influence:
- Mood
- Thinking
- Emotions
- Behavior
Balancing these neurotransmitters helps reduce psychotic symptoms and improve overall functioning.
Benefits of Invega Sustenna
Many healthcare providers recommend Invega Sustenna because of several advantages.
1. Once-Monthly Dosing
Patients do not need to remember daily pills.
2. Better Treatment Adherence
Long-acting injections help ensure medication is received regularly.
3. Stable Drug Levels
The medication remains in the body continuously, reducing fluctuations.
4. Reduced Risk of Relapse
Consistent treatment lowers the chances of symptom recurrence.
5. Professional Administration
Healthcare professionals administer the injection, ensuring proper dosing.
6. Convenient Option
Monthly appointments are easier for some patients than taking medicine every day.
Available Strengths
The injection is available in different strengths:
| Strength |
| 39 mg |
| 78 mg |
| 117 mg |
| 156 mg |
| 234 mg |
The doctor selects the dose according to:
- Medical condition
- Previous treatment
- Kidney function
- Individual response
Recommended Dosage
Only healthcare professionals should administer this medicine.
Initial Dosing
For adults with schizophrenia or schizoaffective disorder:
- Day 1: 234 mg injection
- Day 8: 156 mg injection
These are called loading doses.
Maintenance Dose
After the first two injections:
- Monthly injections begin.
- Maintenance doses range from 39 mg to 234 mg.
Doctors adjust the dosage according to symptom control and side effects.
How Is Invega Sustenna Given?
The medication is injected into:
- Upper arm muscle
- Buttock muscle
A doctor or nurse administers the injection.
Patients should never inject the medicine themselves.
Who Should Not Use Invega Sustenna?
This medicine may not be suitable for everyone.
Avoid using it if you have:
- Allergy to paliperidone
- Allergy to risperidone
- Severe reactions to similar medicines
Older adults with dementia-related psychosis have an increased risk of death and should not use this medication for that purpose.
Common Side Effects
Like all medications, Invega Sustenna may cause side effects.
Common effects include:
Injection Site Pain
Mild pain, redness, or tenderness may occur.
Weight Gain
Some patients experience increased appetite and weight gain.
Sleepiness
Drowsiness and fatigue are common.
Dizziness
Standing up quickly may cause lightheadedness.
Constipation
Digestive problems may develop in some people.
Anxiety or Restlessness
Patients sometimes report feeling restless.
Muscle Stiffness
Tremors or muscle rigidity can occur.
Increased Heart Rate
Some individuals notice palpitations or faster heartbeat.
Serious Side Effects
Although uncommon, serious reactions require immediate medical attention.
Tardive Dyskinesia
Symptoms include:
- Lip smacking
- Tongue movements
- Facial twitching
- Uncontrolled movements
Neuroleptic Malignant Syndrome
Symptoms include:
- High fever
- Severe muscle stiffness
- Fast heartbeat
- Confusion
High Blood Sugar
Signs may include:
- Increased thirst
- Frequent urination
- Hunger
- Fatigue
Low White Blood Cell Count
This can increase infection risk.
Symptoms include:
- Fever
- Chills
- Sore throat
Seizures
Rarely, seizures may occur.
Heart Rhythm Problems
Patients with certain heart conditions may have increased risks.
Warnings and Precautions
Before starting treatment, tell your healthcare provider if you have:
- Diabetes
- Heart disease
- Liver problems
- Kidney disease
- Low blood pressure
- Seizures
- Parkinson’s disease
- History of low white blood cells
- Electrolyte imbalances
Regular follow-up appointments help monitor safety.
Drug Interactions
Some medicines may interact with Invega Sustenna.
Examples include:
Antidepressants
They may increase side effects.
Blood Pressure Medicines
Combining them can increase dizziness.
Sedatives
Sleeping pills and anxiety medicines may cause excessive drowsiness.
Alcohol
Alcohol may worsen dizziness and sleepiness.
Always tell your doctor about:
- Prescription drugs
- Over-the-counter medicines
- Vitamins
- Herbal supplements
Use During Pregnancy and Breastfeeding
Pregnancy requires careful discussion with a healthcare provider.
Using antipsychotics during late pregnancy may affect newborn babies.
Paliperidone can also pass into breast milk.
Never stop treatment suddenly without medical advice.
Missed Dose
Because injections are given monthly, keeping appointments is important.
If an appointment is missed:
- Contact your healthcare provider immediately.
- The doctor will decide how and when to restart treatment.
Do not attempt to compensate by changing doses yourself.
Invega Sustenna vs Oral Antipsychotic Tablets
| Feature | Invega Sustenna | Oral Tablets |
| Frequency | Monthly | Daily |
| Administration | Injection | Pill |
| Medication Adherence | Higher | Depends on patient |
| Convenience | Monthly visits | Daily reminders |
| Blood Level Stability | More consistent | Variable |
Monitoring During Treatment
Doctors may regularly monitor:
- Weight
- Blood sugar levels
- Blood pressure
- Cholesterol
- Kidney function
- Movement disorders
- Mental health symptoms
Routine monitoring helps improve treatment safety.
Frequently Asked Questions
How long does Invega Sustenna take to work?
Some patients notice improvements within several weeks, while full benefits may take a few months.
Is Invega Sustenna a monthly injection?
Yes. After the first two loading doses, injections are usually given once every month.
Can I stop treatment suddenly?
No. Stopping medication without medical supervision may increase the risk of relapse.
Does Invega Sustenna cause weight gain?
Weight gain is a common side effect in some patients.
Is there a generic version?
Currently, no generic version is available.
Can alcohol be consumed during treatment?
Alcohol should generally be avoided because it can increase dizziness and drowsiness.
Conclusion
Invega Sustenna is a long-acting injectable antipsychotic used to treat schizophrenia and schizoaffective disorder. Its monthly dosing schedule helps improve treatment adherence and maintain stable medication levels. While many patients benefit from symptom control and reduced relapse risk, the medicine can also cause side effects that require regular monitoring. Treatment decisions should always be made with a qualified healthcare professional to ensure the safest and most effective care.
