Half-life
~23 hours for the oral form. Paliperidone is the active metabolite of risperidone; long-acting injectable forms (Sustenna, Trinza, Hafyera) self-taper over months.
Withdrawal timeline
Insomnia, nausea, and anxiety are common early. With injectables, there is no abrupt onset - levels fade over weeks to months.
Rebound symptoms and sleep disruption are most prominent in the first couple of weeks after oral cessation.
Acute discontinuation symptoms settle within weeks; relapse of psychosis is a separate, longer risk that warrants close monitoring.
Common symptoms
- Insomnia
- Nausea
- Anxiety or agitation
- Return of underlying symptoms
Less common
- Sweating
- Dizziness
- Tremor
- Vivid dreams
Notable / pattern-defining symptoms
Withdrawal-emergent dyskinesia - involuntary movements that can appear when the dose is lowered or stopped, reflecting dopamine-receptor readaptation.
Supersensitivity relapse - rapid return of psychotic symptoms after abrupt cessation, sometimes more intense than baseline. A key reason to taper.
Tapering guidance
- Taper the oral form gradually rather than stopping abruptly; for injectables, the prescriber manages the spacing or transition.
- Monitor for new involuntary movements and for early signs of relapse.
- Coordinate closely with the prescribing psychiatrist.
Where ketamine therapy fits
Ketamine therapy is not an antipsychotic and does not treat paliperidone withdrawal. In anyone with a psychotic-spectrum diagnosis, ketamine should only be considered in close coordination with the treating psychiatrist, given the theoretical risk of exacerbating psychosis.
Frequently asked questions
How long does Invega withdrawal last?
For the oral form, acute symptoms typically resolve within 2-4 weeks. Long-acting injectables fade over weeks to months, so there is no abrupt withdrawal but a longer tail.
Why is stopping Invega abruptly risky?
Abrupt cessation can cause a rapid, sometimes intensified return of psychotic symptoms (supersensitivity relapse) and withdrawal-emergent movement symptoms. Tapering reduces both.
Can ketamine therapy be used with Invega?
Only in close coordination with the treating psychiatrist. Ketamine is not an antipsychotic substitute, and any plan must account for the underlying diagnosis.
Important: This page is informational and does not constitute medical advice or a recommendation to start, stop, or change any medication. Tapering psychiatric medications should always be coordinated with the prescribing physician. Compounded ketamine for anxiety, depression, PTSD, and chronic pain is not FDA approved.
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