Drug interactions
Perphenazine + Ranolazine
Severity: Major
Perphenazine and Ranolazine: 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
Ranolazine and the phenothiazine perphenazine each prolong the QT interval. Together they increase the chance of torsades de pointes, especially with electrolyte disturbances or structural heart disease. Ranolazine also inhibits CYP2D6, which may raise perphenazine levels.
What this interaction means in plain words
Perphenazine and Ranolazine 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; Ranolazine belongs to Cardiovascular.
Why it happens
Additive QTc prolongation, with possible CYP2D6 inhibition by ranolazine raising perphenazine exposure.
What to do
Avoid the combination where possible, or obtain a baseline and follow-up ECG and correct potassium and magnesium. Consider a lower perphenazine dose or an alternative antipsychotic with less QT effect.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Perphenazine and Ranolazine, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 14 days on the web. No card needed.
Other interactions of Ranolazine
- Adagrasib + Ranolazine Contraindicated
- Amobarbital + Ranolazine Contraindicated
- Apalutamide + Ranolazine Contraindicated
- Butabarbital + Ranolazine Contraindicated
- Carbamazepine + Ranolazine Contraindicated
- Clarithromycin + Ranolazine 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 Ranolazine?
MediHelp rates the interaction as major. Perphenazine and Ranolazine 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. Ranolazine and the phenothiazine perphenazine each prolong the QT interval. Together they increase the chance of torsades de pointes, especially with electrolyte disturbances or structural heart disease. Ranolazine also inhibits CYP2D6, which may raise perphenazine levels.
How serious is the interaction between Perphenazine and Ranolazine?
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, or obtain a baseline and follow-up ECG and correct potassium and magnesium. Consider a lower perphenazine dose or an alternative antipsychotic with less QT effect.
What other medicines interact with Ranolazine?
MediHelp also lists interactions of Ranolazine with, for example, Adagrasib, Amobarbital, Apalutamide. The full list is on the Ranolazine page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
