Drug interactions
Perphenazine + Trimipramine
Severity: Major
Perphenazine and Trimipramine: major 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
Both drugs can prolong the QT interval, so combined use raises the risk of torsades de pointes and other ventricular arrhythmias. Perphenazine also inhibits CYP2D6 and can raise tricyclic concentrations, adding to anticholinergic, sedative and cardiac toxicity.
What this interaction means in plain words
Perphenazine and Trimipramine can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Perphenazine belongs to Central Nervous System; Trimipramine belongs to Central Nervous System.
Why it happens
Additive QT prolongation, with perphenazine inhibiting CYP2D6-mediated metabolism of trimipramine.
What to do
Avoid the combination where possible; if it is necessary, obtain a baseline and follow-up ECG, correct potassium and magnesium, and use the lowest effective trimipramine dose.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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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 Perphenazine
- Ibutilide + Perphenazine Contraindicated
- Perphenazine + Pimozide Contraindicated
- Perphenazine + Thioridazine Contraindicated
- Adagrasib + Perphenazine Major
- Alfentanil + Perphenazine Major
- Amiodarone + Perphenazine Major
Frequently asked questions
Can I take Perphenazine with Trimipramine?
MediHelp rates the interaction as major. Perphenazine and Trimipramine can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Both drugs can prolong the QT interval, so combined use raises the risk of torsades de pointes and other ventricular arrhythmias. Perphenazine also inhibits CYP2D6 and can raise tricyclic concentrations, adding to anticholinergic, sedative and cardiac toxicity.
How serious is the interaction between Perphenazine and Trimipramine?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination where possible; if it is necessary, obtain a baseline and follow-up ECG, correct potassium and magnesium, and use the lowest effective trimipramine dose.
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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