Which drug does not affect warfarin activity ?

Ans. is 'd' i.e., Propylthiouracil INTERACTIONS OF ORAL ANTICOAGULANT The list of drugs and other factors that may affect the action of oral anticoagulant is prodigious and expanding. Any substance or condition may affect oral anticoagulants if it alters 1. The uptake or metabolism of the oral anticoagulant or vitamin K. 2.The synthesis, function or clearance of any factor or cell involved in hemostasis or fibrinolysis. 3. The integrity of any epithelial surface.