Drug interactions
Lapatinib + Quinine
Severity: Major
Lapatinib and Quinine: 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 can prolong the QT interval, so combined use raises the risk of torsades de pointes. Lapatinib is also a CYP3A4 substrate and weak inhibitor, and quinine may alter its exposure.
What this interaction means in plain words
Lapatinib and Quinine 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; Quinine belongs to Anti Parasitic.
Why it happens
Additive QT prolongation through cardiac repolarization (hERG potassium channel) blockade.
What to do
Avoid the combination where possible; if needed, obtain a baseline ECG, correct potassium and magnesium, and repeat ECG monitoring during therapy.
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 Quinine
- Arsenic trioxide + Quinine Contraindicated
- Dofetilide + Quinine Contraindicated
- Dronedarone + Quinine Contraindicated
- Ibutilide + Quinine Contraindicated
- Mefloquine + Quinine Contraindicated
- Nilotinib + Quinine 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 Quinine?
MediHelp rates the interaction as major. Lapatinib and Quinine 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 can prolong the QT interval, so combined use raises the risk of torsades de pointes. Lapatinib is also a CYP3A4 substrate and weak inhibitor, and quinine may alter its exposure.
How serious is the interaction between Lapatinib and Quinine?
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; if needed, obtain a baseline ECG, correct potassium and magnesium, and repeat ECG monitoring during therapy.
What other medicines interact with Quinine?
MediHelp also lists interactions of Quinine with, for example, Arsenic trioxide, Dofetilide, Dronedarone. The full list is on the Quinine page.
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