Drug interactions
Amitriptyline + Flecainide
Severity: Major
Amitriptyline 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
Both agents prolong QRS and QT intervals, so the combination increases proarrhythmic risk, particularly in structural heart disease. Amitriptyline may also compete for CYP2D6, raising levels of either drug.
What this interaction means in plain words
Amitriptyline 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.
Amitriptyline belongs to Central Nervous System; Flecainide belongs to Cardiovascular.
Why it happens
Additive sodium channel blockade and QT prolongation, with possible CYP2D6 competition.
What to do
Avoid if possible or obtain a baseline and follow-up ECG and correct potassium and magnesium; consider an alternative antidepressant such as an SSRI with less cardiac effect.
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 Amitriptyline
- Amitriptyline + Isocarboxazid Contraindicated
- Amitriptyline + Methylene blue Contraindicated
- Amitriptyline + Phenelzine Contraindicated
- Amitriptyline + Pimozide Contraindicated
- Amitriptyline + Procarbazine Contraindicated
- Amitriptyline + Safinamide Contraindicated
Frequently asked questions
Can I take Amitriptyline with Flecainide?
MediHelp rates the interaction as major. Amitriptyline 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 agents prolong QRS and QT intervals, so the combination increases proarrhythmic risk, particularly in structural heart disease. Amitriptyline may also compete for CYP2D6, raising levels of either drug.
How serious is the interaction between Amitriptyline 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 or obtain a baseline and follow-up ECG and correct potassium and magnesium; consider an alternative antidepressant such as an SSRI with less cardiac effect.
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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