Moderate
Probable
Description
Corticosteroids have a complex and variable interaction with warfarin; high doses may increase bleeding risk via GI mucosal effects while also affecting clotting factor synthesis.
Mechanism
High-dose corticosteroids can inhibit synthesis of certain vitamin K–dependent clotting factors and may increase capillary fragility; they also cause GI mucosal irritation, raising hemorrhage risk.
Clinical Significance
The net effect on INR is unpredictable; both increases and decreases have been reported depending on dose and duration.
Management
Monitor INR closely when initiating, adjusting, or stopping corticosteroids; titrate warfarin dose based on measured INR response.