ACEM Primary Pharmacology of Warfarin: the Pharmacokinetics; Pharmacodynamics; Clinical uses; Adverse effects
Over anticoagulation is a common problem with warfarin and acute intoxication maybe in those with or without an anticoagulation requirement. This can make the approach to treatment difficult when considering the need for therapeutic anticoagulation and expert advice maybe required.
An essential co-factor in the synthesis of clotting factors II, VII, IX and X. It is used for the reversal of coumadin-induced coagulopathy.
A 30 year-old female is brought into the ED by her husband. The couple had a heated argument which ended with the patient swallowing ~2mg/kg warfarin.
Little Johnny is an inquisitive 15kg 3 year-old boy. His grandad was looking after him for the evening. About an hour ago, the phone rang just as grandad was about to take his evening warfarin tablets. Although he only turned his back for a second, there was enough time for little Johnny to start ploughing into the tablets...
Warfarin: anticoagulant; prevents the synthesis of vitamin K dependent clotting factors; II, VII, IX & X in liver; prevents the reduction of vitamin K 2, 3-epoxide -> vitamin K