How Long Does Invega Sustenna Stay in Your System
Invega Sustenna (paliperidone palmitate) remains in the system for approximately 4-6 months after the last injection due to its long half-life and extended-release formulation. 1
Pharmacokinetic Profile of Invega Sustenna
Invega Sustenna is a long-acting injectable (LAI) antipsychotic medication used primarily for the treatment of schizophrenia. Its unique pharmacokinetic properties contribute to its extended duration in the body:
Biphasic Release Pattern: After intramuscular injection, Invega Sustenna exhibits a biphasic release profile:
- Initial relatively fast zero-order input that allows rapid attainment of therapeutic concentrations
- Subsequent maintained second-stage, first-order input that allows for once-monthly administration 1
Metabolism and Elimination:
- Paliperidone palmitate dissolves slowly after deep intramuscular injection
- It is then hydrolyzed to paliperidone (the active compound) before being absorbed into systemic circulation
- Approximately 59% of paliperidone is eliminated through the kidneys as unchanged drug 2
- The cytochrome P450 enzyme system plays minimal role in its metabolism 2
Duration in the System
The duration Invega Sustenna remains in your system depends on several factors:
Half-life: Paliperidone has an extended half-life that contributes to its long duration in the body
Formulation Type:
- Invega Sustenna (once-monthly formulation) remains detectable for 4-6 months after the last injection 1, 3
- For comparison, newer formulations like Invega Trinza (three-month formulation) can remain in the system for 9-12 months 4
- The newest formulation, Invega Hafyera (six-month formulation), would remain in the system even longer 5
Individual Factors Affecting Duration:
- Renal Function: Since paliperidone is primarily eliminated through the kidneys, patients with renal impairment may experience prolonged elimination 2
- Body Mass: May affect distribution and elimination
- Age: Older adults may have slower elimination
- Dosage: Higher doses may take longer to be fully eliminated
Clinical Implications of Long Duration
The extended presence of Invega Sustenna in the system has important clinical implications:
Advantages:
- Ensures continuous medication coverage even if a dose is slightly delayed
- Reduces risk of relapse due to non-adherence
- Provides stable plasma concentrations
Considerations:
- Side effects may persist for months after discontinuation
- Switching to other medications requires careful planning due to the long washout period
- Drug interactions may continue for months after the last injection
Important Cautions
Medication Changes: When transitioning from Invega Sustenna to another antipsychotic, the long persistence in the system must be considered to avoid drug interactions or additive side effects
Side Effect Management: Any adverse effects may continue for several months after discontinuation
Monitoring: Regular monitoring for therapeutic effects and side effects should continue for months after the last dose
The extended duration of Invega Sustenna in the system is a key feature of its clinical utility, providing continuous antipsychotic coverage with monthly dosing, but also requiring careful consideration when discontinuing or switching medications.