Anticoagulation in AF is either oral anticoagulants or none .Aspirin has no role in AF therapy .
Warfarin associated skin necrosis is due to early procoagulant state as a result of protein C deficiency .Overlap with heparin prevents this risk.
Warfarin is metabolised by CYP 2C9 .Enzyme inhibitors like Quinolones and Azole products increase bleeding risk , while inducers like Carbamazepine or Gresiofulvin (antifungal) reduce efficacy .
AF in valvular heart disease is treated only with warfarin .No role for NOAC