Drug interactions
Disopyramide + Flecainide
Severity: Major
Disopyramide and Flecainide: major interaction.
Last updated Sources: US FDA label
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 are class I antiarrhythmics with negative inotropic and conduction-slowing effects. Together they can cause marked heart failure, heart block, QRS and QT widening, and ventricular arrhythmia.
What this interaction means in plain words
Disopyramide 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.
Disopyramide belongs to Cardiovascular; Flecainide belongs to Cardiovascular.
Why it happens
Additive sodium channel blockade, negative inotropy and prolonged conduction and repolarization.
What to do
Avoid combining two class I antiarrhythmics. If a switch is required, allow for washout and monitor the ECG and left ventricular function.
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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References
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 Disopyramide
- Amisulpride + Disopyramide Contraindicated
- Desipramine + Disopyramide Contraindicated
- Disopyramide + Dronedarone Contraindicated
- Disopyramide + Itraconazole Contraindicated
- Disopyramide + Ketoconazole Contraindicated
- Disopyramide + Maprotiline Contraindicated
Frequently asked questions
Can I take Disopyramide with Flecainide?
MediHelp rates the interaction as major. Disopyramide 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. Both are class I antiarrhythmics with negative inotropic and conduction-slowing effects. Together they can cause marked heart failure, heart block, QRS and QT widening, and ventricular arrhythmia.
How serious is the interaction between Disopyramide 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 combining two class I antiarrhythmics. If a switch is required, allow for washout and monitor the ECG and left ventricular function.
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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