Drug interactions
Perhexiline + Perphenazine
Severity: Moderate
Perhexiline and Perphenazine: 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
Perhexiline has a narrow therapeutic index and is cleared mainly by CYP2D6. Perphenazine is a CYP2D6 substrate and can compete with or inhibit this pathway, which may raise perhexiline concentrations and increase the risk of hepatotoxicity, neuropathy and hypoglycemia. Perhexiline can also inhibit perphenazine metabolism, increasing antipsychotic adverse effects.
What this interaction means in plain words
Perhexiline and Perphenazine 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
Competitive inhibition of CYP2D6-mediated metabolism of both drugs, with perhexiline itself a potent CYP2D6 inhibitor.
What to do
Monitor perhexiline plasma concentrations and adjust the dose accordingly, and watch for liver enzyme elevation and neurological signs. Monitor the patient for extrapyramidal symptoms and sedation from perphenazine.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Perhexiline and Perphenazine, 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 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 Perhexiline with Perphenazine?
MediHelp rates the interaction as moderate. Perhexiline and Perphenazine 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. Perhexiline has a narrow therapeutic index and is cleared mainly by CYP2D6. Perphenazine is a CYP2D6 substrate and can compete with or inhibit this pathway, which may raise perhexiline concentrations and increase the risk of hepatotoxicity, neuropathy and hypoglycemia. Perhexiline can also inhibit perphenazine metabolism, increasing antipsychotic adverse effects.
How serious is the interaction between Perhexiline and Perphenazine?
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 perhexiline plasma concentrations and adjust the dose accordingly, and watch for liver enzyme elevation and neurological signs. Monitor the patient for extrapyramidal symptoms and sedation from perphenazine.
What other medicines interact with Perphenazine?
MediHelp also lists interactions of Perphenazine with, for example, Ibutilide, Pimozide, Thioridazine. The full list is on the Perphenazine 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.
