Drug interactions
Crizotinib + Flecainide
Severity: Major
Crizotinib and Flecainide: 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
Crizotinib can prolong the QT interval and cause bradycardia, while flecainide slows cardiac conduction. The combination increases the risk of serious ventricular arrhythmias.
What this interaction means in plain words
Crizotinib and Flecainide 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.
Crizotinib belongs to Oncology; Flecainide belongs to Cardiovascular.
Why it happens
Additive QT prolongation and conduction effects, with possible additive bradycardia.
What to do
Avoid if possible; otherwise monitor ECG and electrolytes regularly and correct abnormalities. Watch heart rate and stop or reduce crizotinib if QTc becomes markedly prolonged.
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 Flecainide
- Flecainide + Nirmatrelvir Contraindicated
- Flecainide + Nirmatrelvir / ritonavir Contraindicated
- Flecainide + Pimozide Contraindicated
- Flecainide + Ritonavir Contraindicated
- Flecainide + Thioridazine Contraindicated
- Flecainide + Tipranavir Contraindicated
Other interactions of Crizotinib
- Crizotinib + Flibanserin Contraindicated
- Crizotinib + Lomitapide Contraindicated
- Crizotinib + Lonafarnib Contraindicated
- Crizotinib + Pimozide Contraindicated
- Crizotinib + Saquinavir Contraindicated
- Crizotinib + Thioridazine Contraindicated
Frequently asked questions
Can I take Crizotinib with Flecainide?
MediHelp rates the interaction as major. Crizotinib and Flecainide 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. Crizotinib can prolong the QT interval and cause bradycardia, while flecainide slows cardiac conduction. The combination increases the risk of serious ventricular arrhythmias.
How serious is the interaction between Crizotinib and Flecainide?
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 if possible; otherwise monitor ECG and electrolytes regularly and correct abnormalities. Watch heart rate and stop or reduce crizotinib if QTc becomes markedly prolonged.
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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