Drug interactions
Flecainide + Fluconazole
Severity: Major
Flecainide and Fluconazole: 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
Fluconazole can prolong the QT interval, and flecainide has proarrhythmic effects and slows cardiac conduction. Combining them may raise the risk of ventricular arrhythmias, particularly in structural heart disease or electrolyte disturbance.
What this interaction means in plain words
Flecainide and Fluconazole 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.
Flecainide belongs to Cardiovascular; Fluconazole belongs to Anti Fungals.
Why it happens
Additive effects on cardiac conduction and repolarization.
What to do
Obtain a baseline ECG, correct potassium and magnesium, and monitor the ECG during co-therapy. Consider an alternative antifungal if the QT interval lengthens.
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 Fluconazole
- Dihydroergotamine intranasal + Fluconazole Contraindicated
- Dihydroergotamine + Fluconazole Contraindicated
- Dofetilide + Fluconazole Contraindicated
- Dronedarone + Fluconazole Contraindicated
- Erythromycin + Fluconazole Contraindicated
- Flibanserin + Fluconazole Contraindicated
Other interactions of Flecainide
- Flecainide + Nirmatrelvir Contraindicated
- Flecainide + Nirmatrelvir / ritonavir Contraindicated
- Flecainide + Pimozide Contraindicated
- Flecainide + Ritonavir Contraindicated
- Flecainide + Thioridazine Contraindicated
- Flecainide + Tipranavir Contraindicated
Frequently asked questions
Can I take Flecainide with Fluconazole?
MediHelp rates the interaction as major. Flecainide and Fluconazole 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. Fluconazole can prolong the QT interval, and flecainide has proarrhythmic effects and slows cardiac conduction. Combining them may raise the risk of ventricular arrhythmias, particularly in structural heart disease or electrolyte disturbance.
How serious is the interaction between Flecainide and Fluconazole?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Obtain a baseline ECG, correct potassium and magnesium, and monitor the ECG during co-therapy. Consider an alternative antifungal if the QT interval lengthens.
What other medicines interact with Fluconazole?
MediHelp also lists interactions of Fluconazole with, for example, Dihydroergotamine intranasal, Dihydroergotamine, Dofetilide. The full list is on the Fluconazole page.
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