Flecainide and Darifenacin Interaction
Drug interaction information between Flecainide and Darifenacin.
Flecainide and Darifenacin have a documented moderate interaction in FDA labeling.
FDA drug labeling documents a moderate-severity interaction between Flecainide and Darifenacin. This page displays the available source-record category and label text. The category is not an individual risk estimate or medication-combination direction.
How They Interact
Darifenacin interferes with the enzyme that clears flecainide from your system. This can cause the heart medicine to reach high levels in your body that could be toxic.
FDA Label Information
7 DRUG INTERACTIONS Caution should be taken when darifenacin extended-release tablets are used concomitantly with medications that are predominantly metabolized by CYP2D6 and which have a narrow therapeutic window, such as flecainide, thioridazine and tricyclic antidepressants ( 7.2 ) The concomitant use of darifenacin extended-release tablets with other anticholinergic agents may increase the frequency and/or severity of dry mouth, constipation, blurred vision and other anticholinergic pharmacological effects. 7.3 CYP2D6 Substrates Caution should be taken when darifenacin extended-release...
Flecainide Also Interacts With
- Nirmatrelvir/Ritonavir major
- Fluoxetine moderate
- Propranolol minor
- Diltiazem minor
- Nifedipine minor
Darifenacin Also Interacts With
- Thioridazine moderate
- Itraconazole moderate
- Fluoxetine minor
- Duloxetine minor
- Estradiol minor
Frequently Asked Questions
What SPL severity band is on file for Flecainide + Darifenacin?
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?
Flecainide has 22 labeled pairs on file vs Darifenacin's 18. In the moderate band specifically: Flecainide has 2 (also Fluoxetine); Darifenacin has 3 (also Thioridazine, Itraconazole).
What mechanism field is on file for Flecainide and Darifenacin?
Darifenacin interferes with the enzyme that clears flecainide from your system. This can cause the heart medicine to reach high levels in your body that could be toxic.
Flecainide carries more major-labeled pairs than Darifenacin
SPL source-record counts only. This page's band is moderate · classes on file: Flecainide (Class IC Antiarrhythmic); Darifenacin (Anticholinergic (Overactive Bladder)).
Flecainide has 1 major-labeled pair vs Darifenacin's 0. This page itself is in the moderate band, not the major band.
1 major · 2 moderate · 19 minor · 22 total
- Other moderate peers for Flecainide
- Fluoxetine
0 major · 3 moderate · 15 minor · 18 total
- Other moderate peers for Darifenacin
- Thioridazine
- Itraconazole
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.
Read our methodology - how this data is sourced, computed, and verified.