Drug interactions
Cimetidine + Ranolazine
Severity: Moderate
Cimetidine and Ranolazine: 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
Cimetidine may moderately raise ranolazine concentrations, increasing QT prolongation and dose-related side effects such as dizziness and nausea. Ranolazine is sensitive to CYP3A4 inhibitors.
What this interaction means in plain words
Cimetidine and Ranolazine 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.
Cimetidine belongs to Gastrointestinal Tract; Ranolazine belongs to Cardiovascular.
Why it happens
Cimetidine inhibits CYP3A4 and may also inhibit renal transport (P-gp/OCT), reducing ranolazine clearance.
What to do
Monitor for dizziness, nausea and QTc prolongation, and limit the ranolazine dose if adverse effects arise. Consider famotidine.
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 Cimetidine
- Cimetidine + Dofetilide Contraindicated
- Cimetidine + Fezolinetant Contraindicated
- Alfentanil + Cimetidine Major
- Atazanavir + Cimetidine Major
- Carmustine + Cimetidine Major
- Cimetidine + Citalopram Major
Other interactions of Ranolazine
- Adagrasib + Ranolazine Contraindicated
- Amobarbital + Ranolazine Contraindicated
- Apalutamide + Ranolazine Contraindicated
- Butabarbital + Ranolazine Contraindicated
- Carbamazepine + Ranolazine Contraindicated
- Clarithromycin + Ranolazine Contraindicated
Frequently asked questions
Can I take Cimetidine with Ranolazine?
MediHelp rates the interaction as moderate. Cimetidine and Ranolazine 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. Cimetidine may moderately raise ranolazine concentrations, increasing QT prolongation and dose-related side effects such as dizziness and nausea. Ranolazine is sensitive to CYP3A4 inhibitors.
How serious is the interaction between Cimetidine and Ranolazine?
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 for dizziness, nausea and QTc prolongation, and limit the ranolazine dose if adverse effects arise. Consider famotidine.
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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