Drug interactions
Lapatinib + Lomitapide
Severity: Major
Lapatinib and Lomitapide: 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, a CYP3A4 inhibitor, can markedly increase lomitapide exposure. This raises the risk of hepatotoxicity and gastrointestinal adverse effects.
What this interaction means in plain words
Lapatinib and Lomitapide 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; Lomitapide belongs to Cardiovascular.
Why it happens
Lapatinib inhibits CYP3A4 metabolism of lomitapide, a sensitive CYP3A4 substrate.
What to do
Avoid the combination where possible, and if lapatinib is essential, reduce or suspend lomitapide and monitor liver enzymes closely.
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 Lapatinib
- Dofetilide + Lapatinib Contraindicated
- Ibutilide + Lapatinib Contraindicated
- Lapatinib + Pimozide Contraindicated
- Lapatinib + Saquinavir Contraindicated
- Lapatinib + Thioridazine Contraindicated
- Adagrasib + Lapatinib Major
Other interactions of Lomitapide
- Aprepitant + Lomitapide Contraindicated
- Clarithromycin + Lomitapide Contraindicated
- Crizotinib + Lomitapide Contraindicated
- Diltiazem + Lomitapide Contraindicated
- Efavirenz + Lomitapide Contraindicated
- Ensitrelvir + Lomitapide Contraindicated
Frequently asked questions
Can I take Lapatinib with Lomitapide?
MediHelp rates the interaction as major. Lapatinib and Lomitapide 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, a CYP3A4 inhibitor, can markedly increase lomitapide exposure. This raises the risk of hepatotoxicity and gastrointestinal adverse effects.
How serious is the interaction between Lapatinib and Lomitapide?
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, and if lapatinib is essential, reduce or suspend lomitapide and monitor liver enzymes closely.
What other medicines interact with Lapatinib?
MediHelp also lists interactions of Lapatinib with, for example, Dofetilide, Ibutilide, Pimozide. The full list is on the Lapatinib page.
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