Drug interactions
Cimetidine + Perhexiline
Severity: Major
Cimetidine and Perhexiline: 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
Perhexiline has a narrow therapeutic index and is cleared mainly by CYP2D6, so cimetidine may raise its levels. This could increase the risk of hepatotoxicity and peripheral neuropathy.
What this interaction means in plain words
Cimetidine and Perhexiline 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.
Why it happens
Cimetidine inhibits CYP2D6, the main enzyme metabolizing perhexiline.
What to do
Prefer an alternative acid suppressant such as famotidine or a proton pump inhibitor. If combined, monitor perhexiline plasma concentrations, liver function and neurological symptoms.
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 Cimetidine
- Cimetidine + Dofetilide Contraindicated
- Cimetidine + Fezolinetant Contraindicated
- Alfentanil + Cimetidine Major
- Atazanavir + Cimetidine Major
- Carmustine + Cimetidine Major
- Cimetidine + Citalopram Major
Frequently asked questions
Can I take Cimetidine with Perhexiline?
MediHelp rates the interaction as major. Cimetidine and Perhexiline 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. Perhexiline has a narrow therapeutic index and is cleared mainly by CYP2D6, so cimetidine may raise its levels. This could increase the risk of hepatotoxicity and peripheral neuropathy.
How serious is the interaction between Cimetidine and Perhexiline?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Prefer an alternative acid suppressant such as famotidine or a proton pump inhibitor. If combined, monitor perhexiline plasma concentrations, liver function and neurological symptoms.
What other medicines interact with Cimetidine?
MediHelp also lists interactions of Cimetidine with, for example, Dofetilide, Fezolinetant, Alfentanil. The full list is on the Cimetidine page.
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