Drug interactions
Lapatinib + Mobocertinib
Severity: Major
Lapatinib and Mobocertinib: 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
Both drugs prolong the QT interval, and lapatinib may increase mobocertinib exposure through CYP3A4 inhibition. The combined effect raises the risk of torsades de pointes and other serious arrhythmias.
What this interaction means in plain words
Lapatinib and Mobocertinib 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
Additive QTc prolongation plus CYP3A4 inhibition raising mobocertinib levels.
What to do
Avoid the combination if possible. If unavoidable, reduce the mobocertinib dose by about half and monitor ECG and electrolytes frequently.
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
Frequently asked questions
Can I take Lapatinib with Mobocertinib?
MediHelp rates the interaction as major. Lapatinib and Mobocertinib 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. Both drugs prolong the QT interval, and lapatinib may increase mobocertinib exposure through CYP3A4 inhibition. The combined effect raises the risk of torsades de pointes and other serious arrhythmias.
How serious is the interaction between Lapatinib and Mobocertinib?
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 if possible. If unavoidable, reduce the mobocertinib dose by about half and monitor ECG and electrolytes frequently.
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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