Flecainide and Diltiazem Interaction
Drug interaction information between Flecainide and Diltiazem.
Flecainide and Diltiazem have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Flecainide and Diltiazem. 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
There is not enough medical information available to know how these two drugs interact when used together.
FDA Label Information
There has been too little experience with the coadministration of flecainide acetate with nifedipine or diltiazem to recommend concomitant use.
Flecainide Also Interacts With
- Nirmatrelvir/Ritonavir major
- Darifenacin moderate
- Fluoxetine moderate
- Propranolol minor
- Nifedipine minor
Diltiazem Also Interacts With
- Ezetimibe major
- Ezetimibe/Simvastatin major
- Simvastatin major
- Theophylline major
- Rifampin moderate
Frequently Asked Questions
What SPL severity band is on file for Flecainide + Diltiazem?
Compiled FDA labeling labels this pair minor. That is a source-record field, not an individual medication-combination decision.
Which drug in this pair has the larger labeled-interaction portfolio?
Diltiazem has 46 labeled pairs on file vs Flecainide's 22. In the minor band specifically: Flecainide has 19 (also Propranolol, Nifedipine, Carbamazepine, Digoxin); Diltiazem has 35 (also Buspirone, Pravastatin, Lovastatin, Cyclosporine).
What mechanism field is on file for Flecainide and Diltiazem?
There is not enough medical information available to know how these two drugs interact when used together.
Diltiazem carries more major-labeled pairs than Flecainide
SPL source-record counts only. This page's band is minor · classes on file: Flecainide (Class IC Antiarrhythmic); Diltiazem (Calcium Channel Blocker).
Diltiazem has 4 major-labeled pairs vs Flecainide's 1. This page itself is in the minor band, not the major band.
1 major · 2 moderate · 19 minor · 22 total
- Other minor peers for Flecainide
- Propranolol
- Nifedipine
- Carbamazepine
- Digoxin
4 major · 7 moderate · 35 minor · 46 total
- Other minor peers for Diltiazem
- Buspirone
- Pravastatin
- Lovastatin
- Cyclosporine
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.