Drug interactions
Flecainide + Saquinavir
Severity: Major
Flecainide and Saquinavir: 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
Saquinavir prolongs the QT and PR intervals, and flecainide also affects cardiac conduction. Ritonavir-boosted saquinavir may additionally raise flecainide exposure, increasing arrhythmia risk.
What this interaction means in plain words
Flecainide and Saquinavir 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.
Why it happens
Additive QT/PR prolongation, with possible CYP inhibition raising flecainide levels.
What to do
Avoid the combination where possible. If used, monitor ECG and flecainide concentrations and correct electrolytes.
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
Frequently asked questions
Can I take Flecainide with Saquinavir?
MediHelp rates the interaction as major. Flecainide and Saquinavir 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. Saquinavir prolongs the QT and PR intervals, and flecainide also affects cardiac conduction. Ritonavir-boosted saquinavir may additionally raise flecainide exposure, increasing arrhythmia risk.
How serious is the interaction between Flecainide and Saquinavir?
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 where possible. If used, monitor ECG and flecainide concentrations and correct electrolytes.
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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