Drug interactions
Paliperidone + Phenobarbital
Severity: Moderate
Paliperidone and Phenobarbital: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Phenobarbital can lower paliperidone exposure through induction of P-glycoprotein and other clearance pathways, which may reduce antipsychotic efficacy. Both drugs also cause sedation, so central nervous system depression is additive.
What this interaction means in plain words
Paliperidone and Phenobarbital can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Why it happens
Phenobarbital induces P-gp efflux (and renal and metabolic clearance), lowering paliperidone levels, and both agents have additive CNS depressant effects.
What to do
Monitor for loss of psychiatric symptom control and consider a paliperidone dose increase if relapse signs appear. Monitor for excessive sedation, and reassess the dose if phenobarbital is stopped.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Paliperidone
- Ibutilide + Paliperidone Contraindicated
- Paliperidone + Pimozide Contraindicated
- Paliperidone + Vandetanib Contraindicated
- Adagrasib + Paliperidone Major
- Amiodarone + Paliperidone Major
- Amisulpride + Paliperidone Major
Frequently asked questions
Can I take Paliperidone with Phenobarbital?
MediHelp rates the interaction as moderate. Paliperidone and Phenobarbital can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Phenobarbital can lower paliperidone exposure through induction of P-glycoprotein and other clearance pathways, which may reduce antipsychotic efficacy. Both drugs also cause sedation, so central nervous system depression is additive.
How serious is the interaction between Paliperidone and Phenobarbital?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor for loss of psychiatric symptom control and consider a paliperidone dose increase if relapse signs appear. Monitor for excessive sedation, and reassess the dose if phenobarbital is stopped.
What other medicines interact with Paliperidone?
MediHelp also lists interactions of Paliperidone with, for example, Ibutilide, Pimozide, Vandetanib. The full list is on the Paliperidone page.
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