Major
Prednisolone × Warfarin
Glucocorticoids×Vitamin K antagonist anticoagulants
Mechanism
Prednisolone (a systemic glucocorticoid) raises fibrinogen and clotting factors but can also alter warfarin metabolism through liver enzymes. The effect is unpredictable: INR may either drop or rise.
Symptoms
If INR drops: thromboembolic risk (deep vein thrombosis, stroke in atrial fibrillation). If INR rises: gum bleeding, epistaxis, bruising, GI bleeding (amplified by glucocorticoid-induced gastric mucosa injury).
Management
When prednisolone starts, is escalated, or is withdrawn, check INR at 1 week, then every 2 weeks until stable. Titrate warfarin to INR. PPI cover with pantoprazole is mandatory.
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.