<prompt> True about oral anticoagulant warfarin are all EXCEPT:Acts in vivoActs both in vivo and in vitroInterferes with synthesis of Vit KCauses Hematuria  <response>: Oral anticoagulant is warfarin. It is used only in vivo body, not in vitro lab. Warfarin is not used to store blood. It acts by inhibiting Vitamin K. Due to overdose, hematuria is the first manifestation noted. Dose monitoring is done by INR. Antidote of warfarin overdose: Vitamin KPT Prothrombin TimeaPTT activated Partial Thromboplastin TimeAssess activity of Extrinsic coagulation pathway Used when on warfarin treatmentWePT: Warfarin for extrinsic; PT value assessed.Assess activity of Extrinsic coagulation pathway.Used while on heparin treatment.HINT: Heparin for Intrinsic; aPTT value assessed. 