Supratherapeutic INR Without Bleeding — EECC MCQ

Correct answer: C — Withhold warfarin and administer oral vitamin K 1-2 mg — this will gradually reduce INR over 24 hours; IV vitamin K (5-10 mg) and PCC are reserved for INR >8 with active bleeding; repeat INR the next day

Management of supratherapeutic INR without bleeding follows a graded approach per BCSH and ESC guidelines: (1) INR 5-8 without bleeding: withhold warfarin for 1-2 days, no vitamin K needed in most cases, recheck INR; (2) INR >8 without bleeding: withhold warfarin AND give oral vitamin K 1-2 mg (LOW dose — important with mechanical valves to avoid rebound subtherapeutic INR and valve thrombosis from high-dose vitamin K); (3) INR >8 WITH active/significant bleeding: IV vitamin K 5-10 mg + four-factor PCC (for rapid reversal); (4) Life-threatening bleeding: IV vitamin K 5-10 mg + PCC regardless of INR. In mechanical valve patients, LOW-dose vitamin K is preferred because high doses can cause prolonged warfarin resistance and dangerously subtherapeutic anticoagulation for days, risking valve thrombosis.

Reference: BCSH Guidelines; ESC/EACTS (2025): VHD Guidelines