What are the recommended initial dosing guidelines for initiating warfarin therapy in patients with atrial fibrillation?

Recommended initial dosing guidelines for initiating warfarin therapy in patients with atrial fibrillation:

The provided NICE guideline excerpts do not specify exact initial dosing regimens for warfarin initiation in atrial fibrillation. However, they recommend offering a vitamin K antagonist (such as warfarin) if direct-acting oral anticoagulants are contraindicated, not tolerated, or unsuitable for stroke prevention in atrial fibrillation. The guidance emphasizes monitoring anticoagulation control using the international normalized ratio (INR) and calculating time in therapeutic range (TTR) over a maintenance period of at least 6 months, excluding the first 6 weeks of treatment, which implies careful dose titration during initiation ¹.

For detailed dosing, clinicians should follow the British National Formulary (BNF) and MHRA advice, particularly regarding dose adjustments in renal impairment and monitoring requirements ¹.

Summary: Initiate warfarin with careful dose titration guided by INR monitoring, aiming for a therapeutic INR range, and adjust doses accordingly. Specific initial doses are not detailed in the NICE atrial fibrillation guideline but should follow BNF and MHRA recommendations.