Griseofulvin and Warfarin Interaction

Drug interaction information between Griseofulvin and Warfarin.

Griseofulvin and Warfarin have a documented minor interaction in FDA labeling.

FDA drug labeling documents a minor-severity interaction between Griseofulvin and Warfarin. 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

Griseofulvin

Antifungal

Drug B

Warfarin

Vitamin K Antagonist (Anticoagulant)

How They Interact

Griseofulvin makes warfarin less effective by helping the body get rid of it faster.

FDA Label Information

Griseofulvin decreases the activity of warfarin-type anticoagulants, so that patients receiving these drugs concomitantly may require dosage adjustment of the anticoagulant during and after griseofulvin therapy.

Warfarin Also Interacts With

View all Warfarin interactions →

Frequently Asked Questions

What SPL severity band is on file for Griseofulvin + Warfarin?

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?

Warfarin has 163 labeled pairs on file vs Griseofulvin's 12. In the minor band specifically: Griseofulvin has 12 (also Cyclosporine, Drospirenone, Estradiol, Ethinyl Estradiol); Warfarin has 133 (also Atorvastatin, Amlodipine, Omeprazole, Famotidine).

What mechanism field is on file for Griseofulvin and Warfarin?

Griseofulvin makes warfarin less effective by helping the body get rid of it faster.

Warfarin carries more major-labeled pairs than Griseofulvin

SPL source-record counts only. This page's band is minor · classes on file: Griseofulvin (Antifungal); Warfarin (Vitamin K Antagonist (Anticoagulant)).

Warfarin has 2 major-labeled pairs vs Griseofulvin's 0. This page itself is in the minor band, not the major band.

Griseofulvin

0 major · 0 moderate · 12 minor · 12 total

Warfarin

2 major · 28 moderate · 133 minor · 163 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.