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Amitriptyline and Flecainide Interaction

Drug interaction information between Amitriptyline and Flecainide.

Amitriptyline and Flecainide have a documented minor interaction in FDA labeling.

FDA drug labeling documents a minor-severity interaction between Amitriptyline and Flecainide. Major interactions are generally avoided, moderate ones may need monitoring or a dose adjustment, and minor ones are usually low-risk. This page shows the documented mechanism and guidance. Label-documented interactions are not a complete safety review, so always confirm your own medications with a pharmacist or doctor. Educational information, not medical advice.

Drug A

Amitriptyline

Tricyclic Antidepressant (TCA)

Drug B

Flecainide

Class IC Antiarrhythmic

How They Interact

These two drugs compete for the same processing pathway in the liver. Because they are both handled by the same enzyme, the levels of both drugs could increase in your blood.

What To Do

Your doctor should monitor your heart rhythm and blood levels closely if you take these medications together.

FDA Label Information

The drugs that inhibit cytochrome P450 2D6 include some that are not metabolized by the enzyme (quinidine; cimetidine) and many that are substrates for P450 2D6 (many other antidepressants, phenothiazines, and the Type 1C antiarrhythmics propafenone and flecainide).

Frequently Asked Questions

Can I take Amitriptyline and Flecainide together?

This is a minor interaction. Your doctor should monitor your heart rhythm and blood levels closely if you take these medications together.

How serious is the interaction between Amitriptyline and Flecainide?

This interaction is classified as "minor" severity by the FDA. Minor interactions are unlikely to cause significant problems but should still be mentioned to your healthcare provider.

Why do Amitriptyline and Flecainide interact?

These two drugs compete for the same processing pathway in the liver. Because they are both handled by the same enzyme, the levels of both drugs could increase in your blood.

Understanding the Amitriptyline and Flecainide Interaction

FDA-approved prescribing information for these two drugs flags their combination as a minor-severity interaction. Amitriptyline belongs to the Tricyclic Antidepressant (TCA) class and Flecainide belongs to the Class IC Antiarrhythmic class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: These two drugs compete for the same processing pathway in the liver. Severity tiers matter: major flags generally advise avoidance, moderate flags often require monitoring or dose adjustment, and minor flags may only call for awareness.

Context around a specific patient determines real-world impact. Amitriptyline has 21 total documented interactions on file in this dataset, and Flecainide has 22. Each additional medication compounds the interaction surface, which is why pharmacists run full-profile checks rather than evaluating one pair at a time. FDA-derived guidance for this pair is: Your doctor should monitor your heart rhythm and blood levels closely if you take these medications together. Timing of doses, renal and hepatic function, age, and other concurrent prescriptions all shape whether a labeled interaction matters clinically.

An interaction flag is not a verdict. A large share of labeled interactions are managed routinely in clinical practice, the fix may be as simple as spacing doses or adding a monitoring test. Others require the prescriber to choose a different medication entirely. This page surfaces FDA-sourced labeling and openFDA data for educational purposes only; it is not medical advice and cannot account for your full clinical picture. Never start, stop, or adjust either Amitriptyline or Flecainide based on a web page, speak with your prescriber or pharmacist before making any change.

Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. Always consult your healthcare provider about drug interactions.