Drug interactions
Fosphenytoin + Trimipramine
Severity: Moderate
Fosphenytoin 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
Phenytoin induces hepatic enzymes and may lower trimipramine concentrations, reducing antidepressant effect. Tricyclics may also lower the seizure threshold, opposing anticonvulsant effect.
What this interaction means in plain words
Fosphenytoin 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.
Fosphenytoin belongs to Central Nervous System; Trimipramine belongs to Central Nervous System.
Why it happens
Enzyme induction by phenytoin increases trimipramine metabolism, and trimipramine lowers seizure threshold.
What to do
Monitor antidepressant response and consider trimipramine dose adjustment. Monitor seizure control and phenytoin levels.
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
Other interactions of Fosphenytoin
- Dronedarone + Fosphenytoin Contraindicated
- Fosphenytoin + Ledipasvir-sofosbuvir Contraindicated
- Fosphenytoin + Lorlatinib Contraindicated
- Fosphenytoin + Lurasidone Contraindicated
- Fosphenytoin + Ranolazine Contraindicated
- Fosphenytoin + Sofosbuvir-velpatasvir-voxilaprevir Contraindicated
Frequently asked questions
Can I take Fosphenytoin with Trimipramine?
MediHelp rates the interaction as moderate. Fosphenytoin 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. Phenytoin induces hepatic enzymes and may lower trimipramine concentrations, reducing antidepressant effect. Tricyclics may also lower the seizure threshold, opposing anticonvulsant effect.
How serious is the interaction between Fosphenytoin 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 antidepressant response and consider trimipramine dose adjustment. Monitor seizure control and phenytoin levels.
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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