Propafenone and Ketoconazole Interaction

Drug interaction information between Propafenone and Ketoconazole.

Propafenone and Ketoconazole have a documented minor interaction in FDA labeling.

FDA drug labeling documents a minor-severity interaction between Propafenone and Ketoconazole. 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

Propafenone

Class IC Antiarrhythmic

Drug B

Ketoconazole

Azole Antifungal

How They Interact

Ketoconazole slows down the liver's ability to break down propafenone, which can cause the drug to build up in your body.

FDA Label Information

(7.6) 7.1 CYP2D6 and CYP3A4 Inhibitors Drugs that inhibit CYP2D6 (such as desipramine, paroxetine, ritonavir, sertraline) and CYP3A4 (such as ketoconazole, ritonavir, saquinavir, erythromycin, grapefruit juice) can be expected to cause increased plasma levels of propafenone.

Frequently Asked Questions

What SPL severity band is on file for Propafenone + Ketoconazole?

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?

Ketoconazole has 113 labeled pairs on file vs Propafenone's 26. In the minor band specifically: Propafenone has 22 (also Erythromycin, Desipramine, Cimetidine, Amitriptyline); Ketoconazole has 85 (also Abiraterone, Acetaminophen/Oxycodone, Alosetron, Amphotericin B).

What mechanism field is on file for Propafenone and Ketoconazole?

Ketoconazole slows down the liver's ability to break down propafenone, which can cause the drug to build up in your body.

Ketoconazole carries more major-labeled pairs than Propafenone

SPL source-record counts only. This page's band is minor · classes on file: Propafenone (Class IC Antiarrhythmic); Ketoconazole (Azole Antifungal).

Ketoconazole has 6 major-labeled pairs vs Propafenone's 1. This page itself is in the minor band, not the major band.

Propafenone

1 major · 3 moderate · 22 minor · 26 total

Ketoconazole

6 major · 22 moderate · 85 minor · 113 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.