This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Pharmacology
Anticoagulant effect of warfarin bus increased by all and the following 
Select and explain. 
A. Cimetidine, B. Phytonadione, C. Amiodarine, D. Phenyl butazone
B: Phytonadione
Answer: B: Phytonadione 
Explanation: Refer KDT 6/e p 602 Vitamin K1 (phytonadione) is the antidote of warfarin It decreases the effect of oral anticoagulants