Drug interactions
Phenobarbital + Trimipramine
Severity: Moderate
Phenobarbital and Trimipramine: 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 adds to trimipramine's sedative effect and induces hepatic enzymes, including CYP3A4, which can reduce trimipramine concentrations and antidepressant effect. Tricyclics can also lower the seizure threshold, which may counteract the anticonvulsant effect.
What this interaction means in plain words
Phenobarbital and Trimipramine 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
Additive CNS depression and enzyme induction increasing the clearance of trimipramine.
What to do
Monitor sedation, seizure control and antidepressant response, and consider trimipramine levels. Raise the tricyclic dose if needed and recheck after phenobarbital changes.
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 Trimipramine
- Disopyramide + Trimipramine Contraindicated
- Dofetilide + Trimipramine Contraindicated
- Ibutilide + Trimipramine Contraindicated
- Isocarboxazid + Trimipramine Contraindicated
- Pentamidine + Trimipramine Contraindicated
- Phenelzine + Trimipramine Contraindicated
Frequently asked questions
Can I take Phenobarbital with Trimipramine?
MediHelp rates the interaction as moderate. Phenobarbital and Trimipramine 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 adds to trimipramine's sedative effect and induces hepatic enzymes, including CYP3A4, which can reduce trimipramine concentrations and antidepressant effect. Tricyclics can also lower the seizure threshold, which may counteract the anticonvulsant effect.
How serious is the interaction between Phenobarbital and Trimipramine?
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 sedation, seizure control and antidepressant response, and consider trimipramine levels. Raise the tricyclic dose if needed and recheck after phenobarbital changes.
What other medicines interact with Trimipramine?
MediHelp also lists interactions of Trimipramine with, for example, Disopyramide, Dofetilide, Ibutilide. The full list is on the Trimipramine page.
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