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Drug interactions

Flecainide + Vandetanib

Severity: Contraindicated

Flecainide and Vandetanib: 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

Vandetanib markedly prolongs the QT interval and carries a boxed warning for torsade de pointes and sudden death. Combining it with flecainide further raises the risk of fatal arrhythmias.

What this interaction means in plain words

Flecainide and Vandetanib 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.

Flecainide belongs to Cardiovascular; Vandetanib belongs to Oncology.

Evidence level: Moderate

Why it happens

Additive effects on cardiac repolarization and conduction.

What to do

Avoid the combination and use an alternative antiarrhythmic. Vandetanib labeling advises against drugs known to prolong QT.

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?

Bring a full list of your medicines, including over-the-counter products, supplements and herbal remedies, to every pharmacy visit.

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Frequently asked questions

Can I take Flecainide with Vandetanib?

MediHelp rates the interaction as contraindicated. Flecainide and Vandetanib 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. Vandetanib markedly prolongs the QT interval and carries a boxed warning for torsade de pointes and sudden death. Combining it with flecainide further raises the risk of fatal arrhythmias.

How serious is the interaction between Flecainide and Vandetanib?

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 use an alternative antiarrhythmic. Vandetanib labeling advises against drugs known to prolong QT.

What other medicines interact with Flecainide?

MediHelp also lists interactions of Flecainide with, for example, Nirmatrelvir, Nirmatrelvir / ritonavir, Pimozide. The full list is on the Flecainide page.

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