Warfarin

F.C., a 58 year old male driver was referred to the Toxicology Service for co-management. A day prior to admission, the patient deliberately ingested a 50-gram pack of rodenticide containing 0.052% coumadin. There was no ingestion of other substances. An hour prior to admission, he repeatedly stabbed himself on the chest using a kitchen knife . The noise created by the activity caught the attention of his wife who rushed him to the nearest hospital. The patient has no previous hospitalizations nor surgical operations . He has neither history of liver diseases nor bleeding tendencies. He is an occasional smoker and used to drink alcoholic beverages daily for 18 years. He denies use of illicit drugs. Vital signs noted at the Emergency Room (ER) were: BP = 120/80; CR = 80/minute; RR = 20/min; Temperature = 37?/span>C. Immediate dressing of the wounds was done and he was scheduled for emergency closed chest tube (CTT) insertion and subxiphoid pericardiotomy. The surgical procedures were done without note of untoward incident. The course in the post-anesthesia care unit (PACU) and the wards were uneventful until the third day of admission when Prothrombin Time showed the following results: Patient = 19 seconds; Control = 13 seconds; Activity = 33%; INR = 1.46   1. What is the mechanism of action of coumadin? A. Inhibition of platelet aggregation B. Acetylcholinesterase enzyme inhibition C. Inhibition of vitamin K-dependent factors synthesis D. Cyclooxygenase enzyme inhibition