Flecainide and Fluoxetine Interaction

Drug interaction information between Flecainide and Fluoxetine.

Flecainide and Fluoxetine have a documented moderate interaction in FDA labeling.

FDA drug labeling documents a moderate-severity interaction between Flecainide and Fluoxetine. This page displays the available source-record category and label text. The category is not an individual risk estimate or medication-combination direction.

Drug A

Flecainide

Class IC Antiarrhythmic

Drug B

Fluoxetine

Selective Serotonin Reuptake Inhibitor (SSRI)

How They Interact

Fluoxetine blocks the enzyme that breaks down flecainide in your body. This can cause flecainide to build up to unsafe levels in your blood.

FDA Label Information

Coadministration of fluoxetine with other drugs that are metabolized by CYP2D6, including certain antidepressants (e.g., TCAs), antipsychotics (e.g., phenothiazines and most atypicals), and antiarrhythmics (e.g., propafenone, flecainide, and others) should be approached with caution. Drugs with a narrow therapeutic index represent the greatest concern (e.g., flecainide, propafenone, vinblastine, and TCAs).

Frequently Asked Questions

What SPL severity band is on file for Flecainide + Fluoxetine?

Compiled FDA labeling labels this pair moderate. That is a source-record field, not an individual medication-combination decision.

Which drug in this pair has the larger labeled-interaction portfolio?

Fluoxetine has 68 labeled pairs on file vs Flecainide's 22. In the moderate band specifically: Flecainide has 2 (also Darifenacin); Fluoxetine has 19 (also Alprazolam, Diazepam, Carbamazepine, Haloperidol).

What mechanism field is on file for Flecainide and Fluoxetine?

Fluoxetine blocks the enzyme that breaks down flecainide in your body. This can cause flecainide to build up to unsafe levels in your blood.

Fluoxetine carries more major-labeled pairs than Flecainide

SPL source-record counts only. This page's band is moderate · classes on file: Flecainide (Class IC Antiarrhythmic); Fluoxetine (Selective Serotonin Reuptake Inhibitor (SSRI)).

Fluoxetine has 6 major-labeled pairs vs Flecainide's 1. This page itself is in the moderate band, not the major band.

Flecainide

1 major · 2 moderate · 19 minor · 22 total

Fluoxetine

6 major · 19 moderate · 43 minor · 68 total

Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. This registry does not provide individual medication-combination directions.