Drug interactions
Dofetilide + Lapatinib
Severity: Contraindicated
Dofetilide and Lapatinib: contraindicated 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 dofetilide has a high intrinsic risk of torsades de pointes. Combined use can further increase this risk.
What this interaction means in plain words
Dofetilide and Lapatinib are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two.
Dofetilide belongs to Cardiovascular; Lapatinib belongs to Oncology.
Why it happens
Additive QT prolongation through cardiac potassium channel blockade.
What to do
Avoid the combination and choose alternative therapy. If lapatinib is essential, an alternative antiarrhythmic strategy should be used.
What to ask your pharmacist
- Is there an alternative to one of these two medicines for me?
- If both are essential, who is monitoring me and how often?
- Which symptoms mean I should stop and seek help straight away?
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Other interactions of Lapatinib
- Ibutilide + Lapatinib Contraindicated
- Lapatinib + Pimozide Contraindicated
- Lapatinib + Saquinavir Contraindicated
- Lapatinib + Thioridazine Contraindicated
- Adagrasib + Lapatinib Major
- Amiodarone + Lapatinib Major
Other interactions of Dofetilide
- Amiodarone + Dofetilide Contraindicated
- Amisulpride + Dofetilide Contraindicated
- Amlodipine-hydrochlorothiazide-valsartan + Dofetilide Contraindicated
- Amlodipine-olmesartan-hydrochlorothiazide + Dofetilide Contraindicated
- Candesartan-hydrochlorothiazide + Dofetilide Contraindicated
- Captopril-hydrochlorothiazide + Dofetilide Contraindicated
Frequently asked questions
Can I take Dofetilide with Lapatinib?
MediHelp rates the interaction as contraindicated. Dofetilide and Lapatinib are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two. Both drugs prolong the QT interval, and dofetilide has a high intrinsic risk of torsades de pointes. Combined use can further increase this risk.
How serious is the interaction between Dofetilide and Lapatinib?
MediHelp rates it contraindicated, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination and choose alternative therapy. If lapatinib is essential, an alternative antiarrhythmic strategy should be used.
What other medicines interact with Lapatinib?
MediHelp also lists interactions of Lapatinib with, for example, Ibutilide, Pimozide, Saquinavir. The full list is on the Lapatinib page.
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