Drug interactions
Tucatinib + Verapamil
Severity: Major
Tucatinib and Verapamil: 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
Tucatinib is a strong CYP3A inhibitor and can raise concentrations of CYP3A substrates such as verapamil. This increases the risk of bradycardia, AV block and hypotension.
What this interaction means in plain words
Tucatinib and Verapamil 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.
Tucatinib belongs to Oncology; Verapamil belongs to Cardiovascular.
Why it happens
Tucatinib inhibits CYP3A4, reducing the metabolism of verapamil.
What to do
Avoid the combination if possible, or use an alternative antihypertensive or rate-control agent. If used, reduce the verapamil dose and monitor heart rate, ECG and blood pressure.
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 Verapamil
- Dofetilide + Verapamil Contraindicated
- Flibanserin + Verapamil Contraindicated
- Lomitapide + Verapamil Contraindicated
- Lonafarnib + Verapamil Contraindicated
- Pimozide + Verapamil Contraindicated
- Acebutolol + Verapamil Major
Other interactions of Tucatinib
- Cisapride + Tucatinib Contraindicated
- Eletriptan + Tucatinib Contraindicated
- Ergotamine + Tucatinib Contraindicated
- Flibanserin + Tucatinib Contraindicated
- Ranolazine + Tucatinib Contraindicated
- Amobarbital + Tucatinib Major
Frequently asked questions
Can I take Tucatinib with Verapamil?
MediHelp rates the interaction as major. Tucatinib and Verapamil 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. Tucatinib is a strong CYP3A inhibitor and can raise concentrations of CYP3A substrates such as verapamil. This increases the risk of bradycardia, AV block and hypotension.
How serious is the interaction between Tucatinib and Verapamil?
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, or use an alternative antihypertensive or rate-control agent. If used, reduce the verapamil dose and monitor heart rate, ECG and blood pressure.
What other medicines interact with Verapamil?
MediHelp also lists interactions of Verapamil with, for example, Dofetilide, Flibanserin, Lomitapide. The full list is on the Verapamil page.
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