Drug interactions
Lapatinib + Ranolazine
Severity: Major
Lapatinib 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
Lapatinib inhibits CYP3A4 and P-glycoprotein, which can raise ranolazine concentrations, and both drugs may prolong the QT interval. Higher ranolazine exposure increases dose-related QT prolongation and adverse effects such as dizziness and nausea.
What this interaction means in plain words
Lapatinib 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.
Lapatinib belongs to Oncology; Ranolazine belongs to Cardiovascular.
Why it happens
Inhibition of CYP3A4 and P-glycoprotein by lapatinib reduces ranolazine clearance, with additive QT effects.
What to do
Avoid combining if possible, since moderate to strong CYP3A4 inhibitors are not recommended with ranolazine. If used, restrict ranolazine dose and monitor ECG and 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 Ranolazine
- Adagrasib + Ranolazine Contraindicated
- Amobarbital + Ranolazine Contraindicated
- Apalutamide + Ranolazine Contraindicated
- Butabarbital + Ranolazine Contraindicated
- Carbamazepine + Ranolazine Contraindicated
- Clarithromycin + Ranolazine Contraindicated
Other interactions of Lapatinib
- Dofetilide + Lapatinib Contraindicated
- Ibutilide + Lapatinib Contraindicated
- Lapatinib + Pimozide Contraindicated
- Lapatinib + Saquinavir Contraindicated
- Lapatinib + Thioridazine Contraindicated
- Adagrasib + Lapatinib Major
Frequently asked questions
Can I take Lapatinib with Ranolazine?
MediHelp rates the interaction as major. Lapatinib 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. Lapatinib inhibits CYP3A4 and P-glycoprotein, which can raise ranolazine concentrations, and both drugs may prolong the QT interval. Higher ranolazine exposure increases dose-related QT prolongation and adverse effects such as dizziness and nausea.
How serious is the interaction between Lapatinib 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 combining if possible, since moderate to strong CYP3A4 inhibitors are not recommended with ranolazine. If used, restrict ranolazine dose and monitor ECG and symptoms.
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.
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