Pharmacology General d23c28d0 Anticoagulant not used in vitro is - A Heparin B Warfarin C Oxalate D Citrate High-Yield Explanation Ans. is 'b' i.e., Warfarin o Oral anticoagulants have only in vivo action (not in vitro). o Heparin is used both in vivo and in vitro. o Oxalate and citrate are used in vivo.